Yeah, it's all cleanish inside the engine, if not spotless. It's done 134k but has been a farm hack for a while, so service history is conspicuous by its absence.
Having looked into and having seen some other videos it looks like a big end shell has spun, and it's just enough for the piston to tap the head. I've ordered some shells for £18 and I'll see if it makes a difference. If not that's when the harder choices come in.
I bought it needing some suspension work but didn't hear the engine noise till half way home. End of the day for the £120 I paid I'm not going to lose out, just had hoped to get it mot'd quickly for a friend to use while she's back from Australia.
I have a Y reg hatch in the back garden that was going to be stripped for parts, and it might donate it's engine if it comes to it. Depends if I think its worth it.