“This is the real deal and has endured all the way through,” he told The Telegraph, “it is extremely rare.

“To actually sit in a piece of history that is that significant, it really is quite emotional, actually. With all your senses, you can just feel the aura that’s come with it.”

Of the 70 or so flying Spitfires, perhaps only two others compare to MH415, he said. Its sister aircraft, MH434 and the Silver Spitfire, which recently circumnavigated the globe.

The value of vintage aircraft has surged in recent years, with investors drawn away from the oversaturated classic car market. According to those in the industry, prices have doubled since 2016.

The value of MH415 alone has increased by £700,000 since 2021.

Although it would be a record price, £4.5 million could still prove a snip for MH415. Mr Durston said that he was “99.9 per cent sure” that the engine currently in the Spitfire is the same one installed at the Castle Bromwich factory in 1943.

Documents could significantly increase aircraft value

He does not, however, have the original factory documents, complete with serial numbers, to definitely prove it. Were they to emerge at some point, they might add another several hundred thousand pounds to the value of the veteran aircraft.

Not only is the aircraft in excellent, flightworthy condition, but it also has a significant combat record.

In August and September, it was flown on 27 missions by Sqn Ldr Henri Gonay, a Belgian who had evacuated to England after the Fall of France and died nine months later, shortly after D-Day.