This car obviously raced in European hillclimbs, something we didn't know much about in the UK. They were hardly reported in out motor sport magazines.
I have found this image of Henri Burgisser in a Lotus 23C which does not have the coupe body. The photo was taken in 1970 and I wonder whether it is the same car - maybe the owner/builder decided it was no longer competitive in the sports car class and would have more chance as a GT-bodied car.