I've come across the source of your photos and it would appear that this is a quarter-scale styling model for a grp-bodied Plus 4 Morgan.
To quote the article (from TCC 8/86) -
"In 1961 David Hunt was technical and Design Director of Coventry Laminates. His firm and EB Plastics of Stoke-on-Trent were in competition to produce a grp body for the Plus 4 Morgan.
He says the brief was:
1. The new body would fit the existing Plus 4 chassis.
2. That no mechanical changes would be necessary.
3. The design should be recognisable as a Morgan.
4. The car should have style to appeal to European and American markets.
5. It would be helpful to incorporate as many existing components, particularly trim parts, so as to achieve maximum utilisation of existing stocks and supply lines.
A quarter-scale styling model was shown to Peter Morgan and the photos are of that model.
However, EB Plastics won the contract and the closed two-seater Plus 4 Plus was the result."
The article concludes by saying that David Hunt still had the bodyshell of the styling model when the article was written in 1986.
Putting two and two together, I would suggest the Carnut's recent puzzle was the EB Plastics version and that the Morgan Plus 4 Plus was decided upon after EB won the contract.
Therefore the puzzle is a quarter-scale styling model made by Coventry Laminates for a new grp Plus 4 Morgan.
