Gordon Boswell's gift for turning bright ideas into useful, desirable, mass-produced moneymakers has kept him at the chief designer's desk of Masport for 56 years.

At 83, he has twice been called out of retirement to lend his brain to developing new and improved products.

Most days, he is at the company's Mt Wellington Highway headquarters, where he develops prototypes for new concepts. It is also where he has worked on lawnmowers, rotary hoes, wood burners, gas stoves and waste disposers.

Americans just love his newly patented self-propelled lawn mower, which is also a chipper mulcher.

Masport is celebrating its centenary and Mr Boswell was a star guest at a staff reunion of 450 at the weekend and a company dinner last night.

"I'm more of an inventor than a designer," he said. "My thoughts are more towards the practical rather than the exotic ... working out how to make it, sorting out a problem, improving something as a result of customer feedback. But you must keep in mind that it has to make a profit so you must be down to earth in how it can be made and what it's going to cost."

Masport was founded by Reuben Porter, with Harold Mason and Edwin Jones, in central Auckland.

Mr Porter was a "doer rather than a talker" and prospered with a patented valve for milking machines, a marine engine, a refrigerator and a handmower.

His wife, Enid, was the commercial brains, making Masport one of the first companies to have an equal opportunity policy, employing women on the factory floor and ensuring the company retained staff during the 1930s depression.

Import licensing restrictions protected the company's home market.

Mr Porter's son, Fred, was Mr Boswell's brother-in-law.

He coaxed the science student away from the Auckland University chemistry workshop in 1953 to help the family firm's product range expansion.

"He needed someone to work things out," said Mr Boswell. "His interest was in products that would keep the foundry busy with casting work."

Its output shot up in the 1970s after Fred's son, David Porter, suggested making a cast-iron potbelly stove. More than 4000 Pittsburghs were sold in the first year alone.

Mr Porter spoke at the celebration yesterday. Joining in 1961 as an engineering apprentice, he became foundry boss and was director of manufacturing when Masport became a public company in 1984.

He left in 1985, going on to own and run, with brother Tony, the yacht and ship builder McMullen & Wing.

Masport later came under Brierley Investment's control and was sold to a Goldman Sachs JB Were equity fund. Since July 2007, it has been owned by Tom Sturgess.

The company's products are made in China and it sells more than 100,000 lawnmowers in 30 countries.

Mr Porter said: "If Reuben and Fred came back today they would recognise the foundry and the smells and the heat and the noise, but they would say, 'What happened to the manufacturing?'

"But as general manager Steve Hughes says, Masport are manufacturers - they just do it in a different country. It's controlled from New Zealand and that's why Gordon goes in every day to do development work.

"I think Masport has survived - with dignity - after its century."