So the way to proceed is to send the CAA an email with all the details, and after that to send them the papers back .
The CAA now operate a very strict policy that if you ask questions to which the answer is in the regulations they will not answer your question and will just refer you to the regulations so don't expect an answer.
You seem to be massivly over complicating the issue.
FCL 625 applies from
http://eur-lex.europa.eu/LexUriServ/...01:0193:EN:PDF and
http://www.caa.co.uk/docs/33/CAP804rfs.pdf
Read that - and drive up I95 and do any training required and the test.
If it has expired by more than 3 years the examiner cannot sign your rating page and the CAA must endorse the rating on your licence for which there is a fee.