Correct - the only thing which must be valid when you submit your application for licence re-issue is a JAA Class 2 medical.
You will need to
renew (not revalidate) your SEP Class Rating either before or after you receive the licence by flying a renewal LST with an Authorised Examiner.
This is
not the full PPL Skill Test, but will include some pilot navigation, the extent of which is at the Examiner's discretion.
Send
http://www.caa.co.uk/docs/33/srg1102ff.pdf and
http://www.caa.co.uk/docs/33/srg1187...20feb%2009.pdf to the CAA. Of course if you do your SEP Class Rating renewal first, you can send your
http://www.caa.co.uk/docs/33/srg1119ff.pdf to them at the same time and save yourself a stamp!
There is
absolutely no need to ring the CAA! If you do, they will, quite rightly, probably just tell you to read LASORS.