Well, got the engine there Saturday and they stripped it down today. Its the main bearings that have gone. The bloke I bought it off has put it together wrong with the wrong shims meaning there was a lot of pressure on the bearing. Luckily there is not too much damage at all.
Also, the wrong drive shaft bearing or something was fitted but that hasn't caused any problems but has been changed. Other than that its having a new cam chain and a new top ring. He says the piston is fine and the oil ring is too.
It will be back together by tonight and then I need to pick it up and put it back in the bike.
Thanks for all your help, Carl