Prior to the 1958 Empire Games in Cardiff he represented England because he was doing National Service there.
He was told Scotland could not afford to bring him north. "So because I was based there in the forces, I boxed for England until 1958."
When he travelled north from RAF Halton tor the Scottish championships which would determine the team for Cardiff, it was as reigning Olympic lightweight champion from Melbourne. The venue for the Scottish was Edinburgh Music Hall. Dick stopped every opponent, while outside his elder brothers - an Army and a Navy champion - felt obliged to defend family honour when Dick's allegiance was questioned.
This, very belatedly, also explains the official report from the 1956 Melbourne Games which states: "McTaggart fought in the true English tradition of amateur boxing."
The era was amateur boxing's heyday. "I boxed just about every week," Dick recalled in our exclusive interview. Hence a record of 634 contests with 610 wins.
Despite that temporary England connection, Dundee had no doubt where McTaggart's heart lay. In 1957 Lochee and Dudhope Castle boxing clubs presented his family with a television. "We did not have one until after the Olympic Games, so my parents listened to that on the radio. But Scotland's internationals used to be on TV all the time, so the two clubs gave my mother and father a telly.
"None of my family were in Cardiff [where he won gold for Scotland]. They were all in Dundee, yelling and cheering at that black-and-white Ferguson. I remember it well. Down in Wales it was fantastic, like a home crowd. They were all cheering for the Scots boys, the Englishmen, the Welsh. It was like a local fight, and it was great having them behind you."
Four years on, McTaggart travelled to Australia, for the Perth Empire Games. Having stepped up to light welterweight he felt he could win again. He was stunned when the decision went against him, but not as much as his rival, Clement Quartey.
"He fainted when he got the decision," says Dick. "He never won the fight. It should have been me that fainted. I was so shocked. There was an inquiry into it during the Games, but they could not change the result. I went in there thinking I could win the gold again. That would have been nice, but that's the way it goes in boxing. Sometimes you get the decision when you should not have won. Sometimes you lose it when you shouldn't."
Quartey had won light welterweight silver in Rome (Ghana's first Olympic medal) while McTaggart had taken bronze at lightweight as defending champion, beaten by the Pole who went on to win gold. The first UK boxer to compete in three Olympics, McTaggart lost again to a Pole at light-welter (who also then won gold) in 1964.
Harry Carpenter, doyen of commentators, described the Scot as the greatest amateur boxer he had ever seen. Many were mystified that McTaggart never turned pro, despite four-figure offers from promoters such as Jack Solomons and Peter Keenan. In these days £1000 would have bought a comfortable flat.
The medical would have been a problem, he concedes. Indeed, he once told me he doubted if he would be allowed to box amateur at all today. McTaggart was right-handed yet boxed as a southpaw. He was virtually blind in his left eye. "I couldn't see out of it," he said. "The right was very good, still is very good, but I've got glasses on and still can't see out of the left. But that was not the reason I remained amateur. I just didn't fancy fighting for somebody else. They're getting 25% and you're doing all the fighting?
"Trainers get money. I enjoyed life, but when you turned pro it was a different matter altogether. You've got to be dedicated. I wanted to enjoy my life and you could not do both.
"If you wanted to win world titles you had to be dedicated. I smoked, drank and enjoyed myself."
He confesses to having been a 20-a-day man - more at weekends, when he had the odd pint of lager. "But before a fight I wouldn't drink for four or five weeks . . . I smoked all my life, though not in 1956. Somebody said I'd lose weight if I smoked. That's why I started - it doesn't work by the way. I haven't smoked now since 1999.
"Do I feel the better for it? Pocket-wise, yes. Enough to go out for a meal now and then. Not enough to start boxing again." He roars with laughter at the thought.
The trademark spiky crewcut and white boots have gone. The lightning reflexes may be blunter - he will be 80 next year - but his wits seem sharp as ever. He dismisses a brush with prostate cancer, but concedes he is slowing down. "I stopped bowling four years ago. I got to finals but I was never going to be a champion. I want to spend more time with my lovely wife, Doreen."
The sole rewards of his amateur career are trophies, paintings, photos, and other memorabilia, including a vinyl recording of Raymond Glendinning's commentary on his Olympic victory: "It's for one of those old wind-up gramophones, and he is talking like a lord of the realm," he says.
The couple, who live in Barassie, were recently feted at a reception on board Britannia prior to his stint through Alloway in the Queen's Baton Relay. A fairground near his home, on a car park between Tannadice and Dens, helped launch his career. There was a carnival with a boxing booth where 10 shillings [50p] was on offer to anyone who went a round with Billy 'Kid' Andrew. That's where McTaggart shaped his low arm-carriage, pre-dating Muhammad Ali. "I adopted that style because I watched Billy. His eyes - you know, he could see the punches coming, and had very good reflexes. So like him, I used the ropes, waited, and counter-punched."
Latterly, when he struggled to make the 135lb lightweight limit, in the days before black bin bags, the RAF cook sweated in the plastic bags which the butcher meat arrived in. He also sucked lemons, "which I've since been told did no good whatever".
Though he professes to have enjoyed the good life, he did not shirk roadwork. "When I lived in the Cowcaddens, I'd be up at 6am, running for miles before work, along the canals up Port Dundas, and all round Springburn and Cowlairs. It was the only place I could go. I could hardly run down Sauchiehall Street . . . It was fantastic. I had a great life and don't regret never turning pro. I enjoyed it."
He says he will be at the finals in Glasgow. "I think everything has been arranged and there's a possibility I may present medals. That would be great. The atmosphere at the finals in Glasgow will be just like London. I was there too. I got tickets through the ex-boxers, who arranged everything. It was mobbed every session. What an atmosphere. The cheering from the British crowd was fantastic and that's the way it should be, British."
Third youngest of a family of 18, several of whom died before he was born, he was called Richard the third - his father, plus an elder deceased sibling, were both named Richard. He took up boxing at 15 when dad decided the lads were scrapping enough at home.
He won five ABA titles, three at lightweight and two at light-welter, and Olympic lightweight gold in Melbourne plus the Val Barker Trophy for the most stylish boxer - still the only UK recipient. He won European lightweight gold in 1962, Commonwealth gold in 1958 and silver in '62. He was standard-bearer at both the Rome Olympics and Perth Commonwealth Games. Subsequently he coached both Commonwealth and Olympic teams. He was awarded an MBE in 1985 and is in boxing's International Hall of Fame and the Scottish Sport Hall of Fame.