The Dumfries business saw turnover increase from £19.5 million to more than £21m while pre-tax profits rose from £1.2m to £1.84m, although the underlying increase was even greater because of a hike in directors' pay.
Increasing demands from customers to integrate complex technology and communications systems into the vehicles helped to boost performance during the year to March 31, 2011.
In notes to the accounts filed at Companies House, the directors said "constraint" on UK government spending was a concern so more overseas work was being targeted.
Bryan Findlay, managing director, told The Herald the company is in a strong position for further growth. He said: "Things have been difficult in global markets and that is to our benefit to some extent as our vehicles are used worldwide.
"It is a bit early to say we have seen any impact from the Arab Spring, but we are certainly more active in overseas markets in the Middle East and Africa so we are still watching to see how things develop.
"There are obvious pressures on government spending in the military arena plus the reduction in activity in areas such as Afghanistan as we start to look to move out of there."
In April last year Penman acquired Hampshire-based design and vehicle engineering business, Creation UK. The company's first sale of a Creation vehicle was to a new client in Saudi Arabia.
Mr Findlay said: "Creation gives us another string to our bow which we can bring to existing clients but also target new client relationships.
"We have other Penman business in Saudi Arabia but we are working with a local partner company which is a new development. We are hopeful it will spawn a lot more business."
Penman, which also provides its equipment to civilian security firms, believes it will benefit from an increase in vehicles being updated rather than replaced.
Finance director Tony Rogers said: "The size and nature of our business makes us flexible but people taking brand new equipment to market may suffer slightly.
"We see lots of opportunity for vehicle refurbishment and we are keenly placed to be in that marketplace."
Aberdeenshire-based landmine clearance equipment manufacturer Aardvark, which Penman bought in 2007, is experiencing that trend with a growing section of its business made up of servicing vehicles already in use.
Mr Rogers added: "For the year to 2011, the landmine clearance was a fairly minimal part of the whole group whereas a few years back it was bigger.
"For the year in question it was effectively support for equipments which were already in the field.
"However we see the market segment expanding as sign-ups increase to the landmine clearance conventions and attempts to de-mine ordnance from old conflicts increase."
Penman's rise in pre-tax profits was despite directors' pay increasing by more than £500,000.
The directors saw their rewards more than treble from £224,427 to £739,575, with the highest paid increasing from £60,842 to £188,965.
Mr Findlay said: "We are in a good cash position and we have borne risk to get us to this position since our buyout in 2005.
"I don't think the level of reward is unreasonable for the level of risk taken in the business to get it here."
An interim dividend of £5.465 per share was awarded, meaning payouts went from £237,200 to £437,200.
The business employs around 160 people.