To get an SLMG certificate of test on a CAA licence, all that is needed is to do a check ride with an examiner. I did mine near Oxford where there is a selection of motor gliders available and I was amazed at only having to do a 1 hr check ride to get the cherished stamp in my log book.
if you want to know the phone number, I will look it up on receipt of an e-mail request.
Cheers!