I could be completely wrong but having trawled through my archives and asked a few people, I wonder if this car wasn't once a Dave Rutherford built Modsports 4/4?
About 20 years ago, I was offered the remains of one which had been built for a Chris Cooke. It was quite a successful car in the day.
From memory, the car was advertised as a Plus 4 and had a chassis number, can't remember if it had a log book. Space frame chassis too
I think Dave Rutherford built it around 1975/76
In its day, it had a pretty potent all steel Crossflow but had a Pinto when I saw it though.
A bit too radical for me and completely impractical so I passed it on
Arwyn