+1 for Roger Targett as well, another good guy.
Richard Grace at Duxford may also be of help - he ran three Cassutts for quite a while, he's a top bloke, knowledgable and helpful.
Aniother engine lead is AEP, also have a good rep and do the sort of fettling you might be after. Again, they are Continental savvy.
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Will keep my eyes peeled for a +200kt Cassutt whizzing about then...