One point to Arunas for finding the actual base car, one point to Paul Jaray for finding the builder.
The additional information I found: Built on a 1973 Camaro chassis, this coupe was built with a steel body, and aluminum doors and bumpers. Has a modified Mustang hood, and 1971 Plymouth front fenders. Builder Staten Medsker is proud of the European Mercedes-Benz headlights, as they were bright and illegal in the U.S. at the time.
I especially like the result of this puzzle, as I've added to the information available on the internet. Here is the only information which was previously available on this car, and the original images I acquired:
