Laughing, he said he had plenty of time to work on it.
"It's not so bad when you have a seven-day weekend."
The construction went well, he said, as did initial testing flights which were undertaken last October.
"You get the occasional teething problems — a couple of nuts and bolts but no, it all went really well."
It was all about getting the balance absolutely right.
"All the right degrees to the motors and every little detail."
He built the model using plywood and balsa with a fibreglass compound coating, and finished it in a smart semi-gloss in the blue, silver and white Royal New Zealand Air Force livery of the time it served with them.
It is powered by two 235cc petrol engines which provide plenty of power to get it airborne. "It is absolutely beautiful to fly and has no bugs at all — it does everything right."
Because of its size and power it had to be specially certified by Model Flying New Zealand. The pilots who put it through its paces on those occasions were more than satisfied with it.
And Mr Clarke is happy to let the two pilots accordingly registered to fly it do so, even though he can fly it, too.
"No, I choose not to because they're 25 years younger than me and I'm more than satisfied just watching it up there — it's a great thrill for me," he said.
"It's my job now to service it, pack it up, transport it and set it up."
The DC3 is set to make two eight-minute flights on both days of the festival.
The event is one of the biggest on the national radio flying front and draws up to 50 pilots from throughout the country who join the 100 or so local club members to put on displays.
Hawke's Bay Radio Flyers Club captain and event convenor John Sutherland said the club was the only one left in the country staging such large-scale displays.
"We have done a lot of documentation and we have a good rapport with the councils and with our neighbours Ravensdown," Mr Sutherland said, adding the site was away from built-up areas and created no noise issues.
Spectators will be able to see fighters and bombers from WW1 and WW2 along with jets, helicopters and nostalgic aircraft like the DC3.
Mr Clarke said he had six aircraft in his stable but would only be taking the DC3 and a P51 Mustang out.
However, his stable of half-a-dozen is set to grow to seven.
"I've been at this for over 50 years and I haven't got to the end of it yet," he said with a smile.
"I'm halfway through a Mosquito, which I got started on last April."
• The Warbirds Over Awatoto 2018 event will run between 10am and 4pm on Saturday and Sunday. Spectator access is off Waitangi Rd. To help cover costs people are asked to donate $5 for car access. Refreshments will be available on site.