Mainwheel,
As an Aussie licence holder who also has an interest in gaining a JAR B2 licence I have made enquiries to the UK CAA and spoken to other UK licence holders.
The bottom line is you have to start again.
There are no exemptions for non JAA member licence holders and you have to sit all the modules,just like redoing all the basics exams.
Now this I could kind of handle if it was all that is required however if you want your B1/B2 licence to be type rated you will have to resit your type course. If like me you sat yours in Aust(I did mine at QF) it is worthless.JAR requires aircraft type courses to be sat at JAR147 approved training organisations.
I'd say you would have to way up if it is worth it.You'd have to spend months if not a year at least in the UK/Europe sitting the modules and resitting type courses.
I get annoyed that some countries outside Europe/ JAA will now only accept JAR licences and not the CASA licence.
Hope this helps
Chucky