When Holden announced its last model would roll off the assembly line in 2017, Mr Styles dug out the list drawn up from 1984 to 1988, for an architect's library assembled to make sure 85 per cent of the splendid building tucked into Capital Hill was made in Australia.

His role was to document doors and hardware for MGT Architects. Parliament House has 7500 doors in all, and more than twice that number of hinges and handles, like the toilet self-closing hinges P and B Fraser made in Melbourne, and large continuous piano hinges made by Custom Hinges in Adelaide.

From 87 brands and companies on Mr Styles' list, architects working on the lavish project could look over metal finishing specialists in Melbourne, aluminium adjustable door jambs from Brisbane, and a brass foundry door hardware shop in Sydney. There were circular vision panels for doors from Clapton Metal Spinners, Sydney, and lockable slide bolts from the Orb Lock Company, Melbourne, and many more.

Mr Styles hobby these days is designing hardware for doors, but finding manufacturers like a repetition engineer in Toowoomba, who makes the flat-strap pivots he designs, is become almost impossible.

"I have retained an interest and have watched tens of thousands of useful jobs just slide away," Mr Styles said. "Parliament House could not be built again under those [85 per cent Australian-made] conditions," he said.

The companies and brands either changed names, ceased manufacturing or are now importing equivalent products. "It is ironic that the auto industry is closing at a time when the dollar value makes exports possible again," he said.

As designer of some of Parliament House's door furniture, Mr Styles sent his sketches of brass doorknobs to architect Romaldo Giurgola, which the Italian master approved, then asked if they could be leather wrapped.

"Everything was done like that, everything went across his desk," Mr Styles said. "He consulted all the time and he had the flexibility to say, if something wasn't suitable, 'What can we do?'

"Every light fitting, even the clocks, were studied to the nth degree. He had this saying, 'Why can't we get what we want?'"

Mr Styles used a mould of plaster of paris and chicken wire to make the prototypes for the heavy, push-pull handles that he designed for 250 external doors. Lockwood, Melbourne, made the brass plate for the heavy handles, and Dalco, architectural hardware manufacturers also of Melbourne, made the handles. Both companies no longer do that work. Lockwood is now manufacturing in China.

Many years after Parliament House was completed Mr Styles found one of his designs, a bespoke hardware set of handles finished in satin-chrome, attached to a door in a waste hopper outside.

He says building these days comes down to the cheapest products available out of China, and a political philosophy that Australia must be competitive.

"In the United States, they still have a Buy American campaign; we gave up on that when banks became the most important industry in the world," he said.

Pieces of door hardware, generally the out-of-sight items that make a door work, sit about his little office in Canberra's south, along with scraps of sketches and prototypes that resolve design challenges. In his garage a press he bought from the tip for $100 has been recommissioned.

This is a fulfilling distraction from the despair he sometimes feels for the future of 15-year-old boys unsuited for a long academic career, who in a past era would have been highly valued in thousands of workshops that competed for Australian ingenuity.