One of our ten-tenths members
Allen Mead spoke at length to John about the car(s) a while back. He also got some stickers, posters etc and has articles on the 4S as well. As far as I can remember both cars have now been destroyed - one in a racing accident and the other was more recently broken up.
There's a thread
here that talks about the car. I'm sure Allen would be more than happy to give you as much info as he's got (he's rather keen on his Astras!).