It's going to be like saying goodbye to an old friend for John Zeggert when he sends his 1966 Ford Mustang Shelby GT350 across the auction block at the Mecum Indy event on Friuday, May 20.

John Zeggert Mustang

John Zeggert bought his 1966 Ford Mustang Shelby GT350 when it was new and has owned it ever since. (Mecum)

Zeggert bought the legendary sports car in Syracuse in the summer of 1966 and has been its only owner all these years. But he tells Fox News Autos that he’s decided to let it go after an injury made it too difficult to drive the manual transmission-equipped car.

Zeggert recently fell off a roof he was working on and nearly died, breaking several bones, including his hip, in the incident. He’s back on his feet now, but thinks it’s time for someone else to enjoy the car.

"What am I going to do, sit around looking at it until I die?" Zegger joked.

1966 Ford Mustang Shelby GT350

The GT350 is mostly original, but has been updated with a supercharger. (Mecum)

The car itself has sat around for quite some time over the years. Just a week after he purchased it, Zeggert’s job working for GE on Atlas missile guidance systems sent him overseas for a couple of years, so he had to put it on blocks.

A RARE ‘TIME-TRAVELING’ 1965 FORD MUSTANG IS FOR SALE

He said when he returned it was like driving a new car, but he spent much of his professional life on the road, traveling to military facilities in far-flung places like the Aleutian Islands and eastern Turkey near the border with the Soviet Union.

1966 Ford Mustang Shelby GT350

The GT350 has less than 30,000 miles on the odometer. (Mecum)

As a result of his absences, the car has just 29,431 miles on the odometer and retains most of its original components. That includes its transmission and 289 cubic-inch V8, but Zeggert did install a Paxton supercharger that increased the horsepower from 306 to around 500.

MERCEDES-BENZ MAY HAVE JUST SOLD A CAR FOR A RECORD $142 MILLION

Zeggert said It's mostly been a street car, but he did bring it to a track day once. "You had to go out with an instructor for an orientation lap and when he told me if something failed as I was braking at the end of the straight that’d I’d end up in the fence that was the last time I did that," Zeggert said.

1966 Ford Mustang Shelby GT350

The pre-auction estimate for the GT350 is $275,000 to $350,000. (Mecum)

So he bought another Mustang and turned it into a track car instead. He has owned several other American muscle and sports cars over the years, including a couple of 1960s Mustang Shelby GT500s and Shelby Cobras.

Given his penchant for Fords, it was with some sad irony that he lost much of his life savings that was invested in General Motors when the automaker went bankrupt and had to sell nearly all his cars to make up for it.

CLICK HERE TO GET THE FOX NEWS APP

He wasn’t going to give up the GT350 at the time, but is set to see a pretty nice windfall now that he is, with the car estimated to be worth $275,000 to $350,000.

Zeggert isn’t done with Mustangs, however, as he still owns a 2009 Shelby GT500 with an automatic transmission that he’ll be able to keep driving even with his injuries.