The CAA have recently published their replacement to the old CAP53 and 54 called LASORS 2003. It is nowhere near as well written and clear as the old documents, but anyone who has any of these sort of questions would be well-advised to get hold of a copy. I think it costs £10, but unlike almost all other CAA pubs, you get it from the CAA PCL and NOT the normal source of CAA pubs.
The CAA has chosen to ignore or alter so much of the impact of JAR-FCL2, that it is not wise to look at that document and assume that it applies to the UK. The way that the JAA works (or doesn't work) I imagine that the other countries that have "joined" will have as many variations and differences.
I am still wondering why they ever bothered to generate these common JAA requirements, if they immediately all go off on their own with differences and variations.