Guys,
After seeing Richg's Spencer rep, who's pic is now a screen saver on my PC, I had to do my own.
I managed to get 2 for 1 with a registered MC18 near complete spare bike, engine condition unknown.
So since then I have sprayed the wheels, done the fork seals, redoing the brake calipers, brake masters etc.
I started a search for an RS250 single seat and found one in Japan. As I was going there in a couple of weeks I had it sent to my hotel and bought it home as luggage.
I've since spent a lot of time, more than I'd thought on first building a frame to sit it on, then cutting and reshaping the cowling to get all lines right and mounting lined up.
Here are a few pics of my progress (if I can get them uploaded.

