Weirdly, I think I have seen the A35 van, and it is indeed quick (or should I say, was!)
If it is the same one it was used by the owner to tow his single seater to meetings where he raced both and has a well tuned engine (1275, I think) and pretty roughly flared arches. the wheels were, I think, Lola magnesium items. the back end was semi spaceframed I think
rear door was made from a sheet of alloy. When I saw it a few years ago it was (or had been) light metalic blue. It's in a poor state now sadly
There can't have been that many modified A35 vans, and it's still near Edinburgh.
It had a Restall seat to!
Needless to say I'm keeping it's location to myself, as it's safe where it is, and I don't see it going anywhere for a while yet!