World's rarest tractor and designer Carl Upton part of display at 2023 Henty Machinery Field Days

In fact, the 74-year-old Corowa resident insists his real education began when he left at 16.

With a father in the engineering business, a young Carl sort of "grew into" building tractors.

And with a fitting and machining course under his belt, he was soon sent out into the field to fix broken down machines.

"I could see the design flaws in them and the things that needed fixing," he recalls.

So Mr Upton decided to design his own.

This week, five of the six mighty Upton MT-855 tractors he created in 1976 are on display at the Henty Machinery Field Days.

The one-off exhibition of one of the world's rarest tractors is a "history making event", according to Mr Upton.

"We've never had more than two in one spot at one time."

The tractors, which have come from "far and wide", are on loan to the field days from their owners, and many of them are still in magnificent working order.

"Hear that roar?" Mr Upton asked proudly. "That's one of the big girls starting up now."

The MT-855 tractors were created and manufactured at Corowa, more than 50 years ago.

Upton Engineering, which is now run by Mr Upton's sons Paul and Marc, has been in operation in the town for 78 years.

Mr Upton can also lay claim to building the biggest two-wheel drive tractor in the world - the HT 14/350, featuring a 350 horse-power engine.

"It was a monster," he recalls.

"I have a photo of it standing next to a Chamberlain (Australia's then biggest selling tractor) and it's three times the size of it.

"These tractors will never be built again - they were way in advance of anything available at the time."

Mr Upton clearly remembers one of the first Upton MT-855 tractors he sold to a guy in Queensland in the late 1970s.

"He drove it 1600 kilometres from Corowa to Springsure in three days," he says.

"Those old girls were very fast; they could get up to 100 kilometres per hour!"