I use a Raid Snap Off quick release in my Series 3:
Just noticed you live in Stamford, I live in Thurlby near Bourne, if you want to have a look you are quite welcome to pop over. I have just SORN'ed my car so unfortunately cannot bring it to you. Had a look on the web and my one does not seem to be available any more though there is a second hand one on ebay at the moment - http://www.ebay.co.uk/itm/Raid-Snap-Off-Steering-Wheel-Quick-Release-Boss-/252651825949?hash=item3ad338eb1d:g:yeUAAOSw4GVYN2XJ
Nigel.