Dave Gregson?
Dave Gregson is correct.
He built several Austin 750-based specials and the puzzle car is a Mk 3 version loosely based on an Alta design.
How irritating!
I knew Dave Gregson some years ago when I used to handicap an Austin 7 race series for the 750 Motor Club and he turned up in what must have been the first of his cars which was a pretty good likeness of a 1926 GP Delage. It could still have the narrow wheels of course which this one hasn't got.
I thought you might have known him Allan.
Do you know how many cars he built.
As the puzzle car was a Mk.3 perhaps there were only three?
The car was for sale through C.E. Jones fairly recently but their website has now disappeared.