I would love to own something like this one day. Makes me wonder if something similar is possible for vintage sports cars.
This is a thing, and its based on a similar car.
Started out with a built 1640cc VW motor, ended up with a Mazda 13B rotary.
Years later, he offered it to me for free. I turned it down.
My father had a fake lotus racing car in the same vein. Mostly made out of beetle bits and what I suspected was a bathtub. Motor came from a Toyota, with lots of modifications.
I know it did drive, but my memory only includes pushing it up a hill so we could try starting it using gravity.
Costs about $800K USD, which is a few tens of millions less than the real thing. Apparently you also see the GTO cars racing in the classic races, as a stand in when the owner owns the real thing.
As an aside, I think the 250TR is one of the absolute prettiest cars ever built. Prettier even than the 250GTO. I'm equally unlikely to own either though.
He did track days with it, and set very respectable times. (He also raced a 1969 Ford Mustang in the local historic class. He was a fairly fast driver for a club racer. Not professional race driver fast, but he certainly wasn't babying his cars.)
I wouldn't expect them to handle like a modern vehicle, and that's before the lack of crumple zones