What actually fails on the engine, surely It cant be rocket science to rebuild the engine?
Dont buy one to break though, the parts are worth pennies, my dad had a rear ended one, and only the engine was worth a bit, and thats just beacuse it had a rebuild 5k miles prior to the smash, the rest of the bits didnt fetch much at all on ebay?
Just looking under the bonnet would be enough to scare most typical mechanics off. It's called The Rats Nest for a reason