Thanks chaps. Got started with stripping the B12 down this evening. Its a total shed. I though about putting the 750 engine in it but I'd have to spend too much money on it to get it through MOT, safe enough to ride and presentable enough to sell. So its going to be torn down totally for spares.
Spent a few hours on it and got all of the ancilliary stuff off. Amazed it hadnt burnt down to be honest the main fuel line was the worst I have ever seen. Cracked almost all the way through in several places.
Still need to get the chain off, drain oil and drop the oil cooler off. I cant remember if its necessary to take the headers off to get the engine out? I expect it is however I would really rather not try the studs if I can avoid it for obvious reasons. Got all the engine mounts cracked easily so they are ready to go, so that was a result