Andy,
I had thought that holders of FAA PPL/IR were able to exercise IMC proveleges
I don't think it's quite that simple. The holder of an ICAO PPL/IR (including FAA) may apply for an IMC rating to be added to his UK (CAA/JAR) license without requiring any further training. He is not automatically entitled to use his foreign IR in the UK. If the pilot doesn't hold a UK license, then there is no license to which he can add the IMC rating, so this obviously doesn't apply.
At least, that's the way I think it works. But I don't think I'm any less confused than anyone else! Englishal has the right idea, IMHO - if there's any doubt at all, get it in writing from the CAA.
FFF
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