Jolly Good, Alec! (and Roger)
It is indeed a 998cc Austin Mini powered Deep Sanderson 301 LeMans Coupe' that ran at the 1963 LeMans 24 Hours.
The car qualified 47th on the grid with a 5 min-40.9 sec lap.
It was rear-engined (with the Mini powertrain) so it did look somewhat like the Imp-based racers of the time. And naturally, a bit like the Marcos cars too.
Other than the BMC powertrain and wheels, the car was basically scratch-built by Lawrence Tune Engineering, UK.
It was disqualified as a finisher because it was only able to complete 110 laps by the end...not enough (the winning Bandini/Scarfiotti Ferrari did 339 laps).
These '50s and '60s LeMans races had some wonderful cars that could actually be driven on the street. There is a link (below) that shows many of the cars that ran in the '63 LeMans.
Note the neat aero-MGB, the Cobras with aero-hardtops, The Lola Mk 6 (predecessor to the Ford GT), the lightweight Jag E-types, the Lister, the *real* GTOs, the strange Porsche 718, Sunbeam-Talbots, the 1098 Sprite LeMans Coupe', the strange-looking Auto-Union (now Audi). and so forth.
And it's neat to see so many cars racing on wire wheels too.
Here's the link:
https://www.racingsportscars.com/photo/Le_Mans-1963-06-16-photo.html