From my side, sold them all and I see none NOS on the market.
Anyway, there is always a solution to any problem.
What you can do is the old school way : When these lights were in production (I mean Marchal lights till the 80's), you could change the whole light or just the glass.
Then buy a pair of used light like the one Lee mentions;
Buy a set of repros lights for the Renault 12, Turkey produces some, and can be found on the internet. The glass will be convex but the shape is ok; so you will have holders with perfect reflecting chromes
Remove lenses from all lights, give a good clean to the marchal glasses and glue the marchal lights on the repros holders.
Obviously the rear of your light will not have the look of an original marchal but from outside (means looking at the car) it will be perfect.
Best
PS : the only difficulty is to find used lights with no pits on glasses as they were exposed to drive and weather conditions.
Also, bad timing as some time ago, I was sorting out my extra inventory of headlight:
https://www.gt40s.com/threads/original-marchal-headlights-tp21sp.56676/
