A mate of mine and
@DVD had an insane 500+ brake one years ago. Was imported by a local import place and it had been put together in a lab, inside the car was a fixed seat, battery and fuel cell... that was pretty much it! I always fancied one but it's the issues you mention that killed it for me. Most of them are utter rot boxes now and clean one would cost over the odds for what it is. Gearbox wise I think you could probably still source the parts required for a rebuild.
I think that is a car that should have had slightly more iconic status than it did. I remember a couple years ago seeing a few for sale for about 1700 quid and thinking they will end up with the wrong people and be destroyed.
That said tho if you want one.... go for it. Scratch that itch lol.
But sometimes people (myself included) should never meet their heros. For me it was a s2 escort rs turbo. In my mind when I was 15 there was nothing cooler. My 22 year old self disagreed... if it wasn't broken needing fixed it was needing body work and then when it was just about how I imagined it would be... stolen