Futch:
Spyderidol:

Could be the car that won at Vallelunga  yes

 

The only difference I see is that the Follmer/Kausen RSR had a green lip, whilst the sister (van Lennep/Muller) car had the red lip as seen on this car.

Factory prototypes changed appearances a lot during their racing days, R5 was even a totally different model at some stage as a 2.1 Turbo, and at the Nurburgring, it wore a Mary Stuart spoiler.

I will check about Vallelunga, I know it didn't do Le Mans but it won the 1000 km of Dijon in 73.