FILM directors tend to turn up at interviews carrying a Cinemascope-sized confidence and a comparable ego, necessary for the job perhaps, given they’re responsible for controlling multi-million pound budgets and actors’ excesses.

Jon S Baird brings with him a self-assuredness, but also an endearing sense of wide-eyed incredulity. The Scot still can’t quite believe that the wee boy who once dressed up as Stan Laurel for a school fancy dress party has had the chance to direct the new Laurel and Hardy biopic, Stan & Ollie.

“I was invited to a recent pre-Oscars ball,” he says in a North Eastern accent as warm as a fisherman’s jumper, “and the likes of Spielberg, Kidman, Harrison and Hanks, were all there. I looked around the room at one point and I was the only person I recognised who wasn’t famous.”

He laughs, relaxing back in his chair in a Glasgow hotel: “My next thought was, ‘Fit’s a boy fae Peterheid daein here?’”

We come to that journey later, how the son of a construction worker and a nurse come to be not only hobnobbing with showbiz royalty but becoming a serious player in the industry. (Baird has an open invite to “Marty” Scorsese’s house in New York and is “in talks” with James McAvoy about a new project.)

But first, let’s talk Stan & Ollie, starring Steve Coogan and John C. Reilly as the world’s greatest film buffoons. The Scot captures Laurel and Hardy through two very different lenses: we see the bright lights of Hollywood, a sunshine-soaked world of bikinied starlets and plush-lawned mansions – and then switch to miserable, rain-soaked Britain in 1952, where the double act are reduced to touring variety theatres.

Stan and Ollie are not quite washed up, but swimming very hard against the riptide of changing public taste. Baird captures Britain’s social landscape with a perfectly-judged eye, this post-war era of damp candlewick bedspreads, peeling wallpaper and strong tea served in mugs in run-down cafes by women called Doris.

The drama comes from two directions – the audience are anxious to know whether the comedy legends’ determination will be enough to see them survive the small, echoey halls and audiences tinier than Olly’s moustache. And we learn there’s been a schism. Laurel carries the grudge that Hardy let him down, not backing him against the film studio boss when he asked for more money. As a result, Laurel left, and for a time Hardy worked with a new partner.

But rather than feuding like hillbillies the pair emerge as a bickering married couple. We learn that Laurel and Hardy were rather like an American version of Rikki Fulton and Jack Milroy. Stan was the writer, the worrier, the arranger, the grafter. Easy-going Ollie played golf and dated women until time to turn up and film.

So far, so great. But why haven’t we seen a Laurel and Hardy picture before? “I had the same question when I read the script,” says the blond-haired director. “And it’s probably because the rights were so hard to pin down. And while the original idea was to create a biopic for BBC1, ambition soared which meant a different type of rights for a worldwide movie deal. This in turn meant we had to get the blessing of the Laurel family.”

Did that mean diluting the script? For example, Stan and Ollie were two classic Hollywood skirt-chasers, who in turn were ripe for plucking by opportunists. “Yes, they both loved women,” he says with a wry smile. “Ollie was married three times and Stan five. And we could have chosen different points in their lives which would have given the film a darker tone. But you can’t do everything. And you have to remember that Laurel and Hardy were known for a certain type of innocence. All the time you are walking a tightrope.” He adds: “There was a connection with the Scottish-based Laurel and Hardy fan club who kept us right in so many areas.”

The success of the film, however, would be dependent upon finding the actors who could play these giant stars, who could deliver the on-stage routines and the off-stage pathos. Steve Coogan and John C. Reilly, he says, were top of his wish list.

Baird smiles as he recalls how both Coogan and Reilly had been “excited” by the prospect of playing the screen legends. But that emotion was soon replaced. “Then they became really nervous. They both began to think ‘We could really f*** this up if we don’t get it right.’

John Reilly summed up his dilemma perfectly at the time. He said: ‘Playing Oliver Hardy is a terrifying prospect. But what’s even more terrifying is the idea of someone else playing him’.”

Steve Coogan was confident – until it came down to rehearsals. “Thank God they were both nervous at different times. So when one was worried the other would calm him down.”

Baird decided to use budgeted time to rehearse rather than film, to get the routines exactly right. It was the right choice. Compare his film sketch scenes to the originals and it’s hard to tell them apart. What Baird also does cleverly is meld some of Stan and Ollie’s film moments into their real-life story. For example, the classic piano falling back down the apartment block stairs is homaged by a scene in the movie when Ollie’s trunk drops down the steps of a Newcastle railway station.

But not only the actors faced pressure. “The idea of failure was always looming,” says Baird of the £10m movie, “but perhaps thanks to a mix of arrogance – or naivety – we kept going.”

The smile drops from his face for the first time. “The problem in Scotland is we have an incredible ability to put ourselves down. We have inferiority complex bred into us. I try to ignore that, in fact try to go the other way.”

So how did Jon Baird manage to escape the prison town that is Peterhead, and make it to Hollywood? “I grew up in a very normal house,” he recalls. “There was no connection to the arts or showbiz but every year we’d go to London to stay with my uncle, and we’d go to all the musicals. When I saw Oliver! as a nine-year-old I came out of that theatre with a feeling of euphoria I wanted to last forever.”

Did he want to become an actor? Producer? Director? “I just didn’t know,” he grins. The teenage Jon Baird never told a soul of his secret dream. “That would have been like exposing yourself,” he says, breaking into a laugh. “Can you imagine going into a school in Peterhead and saying you wanted to become a theatre director?”

I’m getting the sense you didn’t attend Glee Academy? “No,” he says, in emphatic voice.

On leaving school, Baird tried – and failed – to get into film school. “I still didn’t know what a director actually did.” As a backstop, he studied Politics at Aberdeen University. The day after graduation, Baird upped and moved to London to seek his fortune. And then followed two of the most miserable years of his life, sharing a flat in Docklands with two pals while slogging through call centre jobs or selling advertising space. “I don’t even know what the f*** I was selling,” he recalls with a shake of the head, reflecting his abject misery.

“This period, from 1996-1998, was a really dark time for me. I had pals, but we were all in the same place, going nowhere.”

He shudders: “It was so bad that when I now hear songs from that period I get a cold shiver running through me.”

A friend had suggested Baird should try to land a job as a runner with a TV or film company, to get experience but these first-rung jobs arrive about as often as blokes from Peterhead get to go to Oscars balls.

However, favoured the bold. “A mate who was working on the telesales recruitment section of a newspaper told me he had just had a company try to place an ad looking for a runner,” Baird grins. “He lied – and told them he had no immediate space left in the paper, to give me a chance to apply. I got the number of Prospect Pictures and called them up and said, ‘I hear you’re looking for a runner – I’m your man.’”

After a week’s trial Baird proved he was. “During the week the newspaper ad did run and the company had over 1,000 applications for the job. There was no way I’d have got it given that competition.”

Jon Baird’s father, he recalls, had brought him up with a basic philosophy. ‘Climb higher.’ And that’s what he practised at work. As a film industry gofer he taught himself about film, he blagged the chance to use a camera while working on the likes of regional travel shows or programmes for BBC Choice or Sky Digital. “I now knew I wanted to be a director.”

He tried to climb even higher. He moved to the BBC. “I didn’t want to work on topical comedy shows so I tried to get on a director’s course, to learn how to film dramatic performance. But after several attempts they wouldn’t let me on.”

Baird wouldn’t accept defeat. He left to go freelance and used contacts he’d built up to make a short film. A calling card, in effect. The boldness paid off. “Through that I met a producer, and together we made Cass, [the true-story indie film about a football hooligan-turned crime writer]. Baird wrote the script. “We couldn’t find a writer we liked and who was prepared to work for next to nothing,” he says. “I said, ‘Let me have a go’, and although the first drafts were absolutely terrible, eventually you get into a rhythm.”

Cass was a success. Baird reckoned to climb even higher still. Having read the Irvine Welsh novel Filth and loved it, he wrote a screenplay and pitched it to the writer. Remarkably, Welsh gave it the green light. Yet Filth proved to be an epic five-year battle in raising finance, testing the young director’s resolve to the limit. At one point the film ground to a halt.

“It was tough,” he sighs. “Crew not getting paid, the lot. In the end it was Sting’s wife Trudi Styler who put up the final million needed to keep the cameras rolling.” Did Trudi get her money back? “Yes,” he says with a smile of sheer delight. And Irvine Welsh? Did he like the final result? “When Irvine saw it he kissed me on the forehead and said ‘It’s better than the book.’ He’s a really close pal now.”

Baird was now climbing past the thick branches, defying his Scottishness. In 2014 he directed the television drama Babylon for Channel 4. A year later he was approached by HBO to direct an episode of their Martin Scorcese/Mick Jagger produced show, Vinyl.

Meantime, writer Jeff Pope, who had written film hit Philomena (starring Steve Coogan) was now looking to attach a director to Stan & Ollie. “My agent sent it through thinking it wasn’t my sort of thing. He reckoned I’d be looking for another Filth but he didn’t really know me. I love a love story, and I had tears in my eyes when I read the script.”

Yet the script changed a great deal from that first draft. “There were a lot of peripheral characters involved which we cut down. And the wives [stand-out characters played by Shirley Henderson and Nina Ariande] weren’t in the first draft. But they turned out to almost steal the show.”

The actors, he says, brought a lot to the characters. But did he worry it was all becoming too collegiate? His smile says that was certainly the case. “When you are working with strong-willed actors like Steve and John you have to be very tough. There are times when you have to say ‘No.’ I’m doing it my way.’”

Shades of the Billy Wilder quote, I wonder? "A director must be a policeman, a midwife, a psychoanalyst, a sycophant and a bastard"?

“Well, you’ve got to be more like a parent, or a schoolteacher,” he grins. “And I never get shouty. I actually get embarrassed in social situations. And if you start shouting you lose the argument. So I let the actors shout themselves out of it. But usually it’s not about ego, it’s about people who want to do the best job.”

Baird, who now lives in Surrey with his wife and daughter, pulled a masterstroke in hiring the services of prosthetics genius Mark Coulier. John C. Reilly’s physical resemblance to Oliver Hardy is uncanny, thanks to four hours transformation each day. “John would even weigh his fat suit down to make him move like a man who’s 20-odd stone. The suit had a water cooler designed into it, to keep John alive.”

Steve Coogan, like Reilly, had reverse-coloured contact lenses fitted. “He also had his ears pinned forward and his chin extended to help create Stan.”

The result will see Baird move towards the top of the tree. Variety has described his film "Irresistible."

But his delight is contained. “My big regret is that my dad died 15 years ago, so he hasn’t a chance to see the success,” he says, his voice tinged with sadness.

Yet, the 45 year-old director still can’t quite believe what he’s achieved. “I was the small eight year-old who used to run home from school to watch Laurel and Hardy re-runs,” he proclaims in defiant voice. “I dressed as Stan for a fancy dress competition – and now I’ve made a movie about them. How incredible is that?”

Does he have regrets about the journey so far? “None,” he says, smiling. “Not even the call centre jobs. Looking back, I’m glad I went through that. It makes you tougher. It makes you appreciate what you have now.”

When you throw the last question at Jon S. Baird - what’s the ‘S’ for? – the sense of humility is reinforced. “Summers,” he says. “My grandmother was Jane Summers and I always said if I did anything with my life I’d add the ‘S’ as a tribute. But a lot of people think it’s because I’m trying to be a dick. That’s not true at all.”

He’s earned the ‘S’ you suggest. “I hope so,” he says, smiling. “I hope people love this film.”

Stan & Ollie (PG) is out on January 11