Ed,
No problem, it was your statement :
Very few UK clubs will actually let you fly their a/c since they feel that they have lost money that you gave to the US and you have skipped the 'Weather Drag Curve' e.t.c. of the UK. They also will make you go through practically everything with 1 of their instructors before they put you in for a skills test with an examiner (For the UK JAR-FCL licence).
That led me to believe that you had been told you HAD to do it. If you are doing it for yourself then thats fair enough - its recognising your own personal limits/comfort zone.
I have only heard of 1 instance of someone getting told he would need extra training, i think a figure of 15 hrs was mentioned, when the instructor had found out he had a US PPL and had not even flown with him yet - he walked away. I came back from the US with a 'whopping' 62.5 hrs
and did a checkout with instructor at Bournemouth who was happy to cut me loose afterwards. I did the same at WLAC and was signed off.
The radio and airspace is different but not that much, I found the easiest(and cheapest hehe) way to get used to it was bum a lift with another pilot and just observe.
Good luck with exams and GFT!
J.