Can I end this post by saying that after all my concerns, I was lucky enough to be doing the NCT test in Deans Grange (grandkids had a great time discovering the wonders of the local graveyard - for example, 'do the dead people escape through those holes in the graves'). Anyway, there's a garage right across the laneway from the NCT testing centre (coincidence!) and a wonderful immigrant from eastern Europe opened up the boot door, somehow magically easily took off the plastic housing from the rear middle brake light, took out the bulb effortlessly (I'd read that you almost need asbestos hands to do same!), looked at it, said he thought he had similar, happened to have it, replaced it, Bob's your uncle, magic, it worked. Strolled across to the NCT test centre, grapped one of the 'inspectors', showed him the light working, and hey presto, I now have an NCT Cert.