Thanks , especially LownSlow for the advice. I will get an engineer I know locally to look at the Cessna, assuming he can get at all the bits-it's at the back of a garden under a lean-to! No I won't get involved with the rebuild probably, although it is tempting as a project. Is the local hangar at Fowlmere you mentioned? I suppose a rebuilt Continental engine to suit the 150 would set one back about £7-10K?
I have already mailed the US Cessna 150 Club but no answer yet.