Rubber bumper filler
 

I recently bought a 1974 Challenger and removed a three piece rubber filler that goes between the body and rear bumper. It has a long straight piece (with metal attachment) for the center, along with two end pieces that screw into the rear fenders at the back corners. I have seen it on some other Challengers (in photos). I want to know what these pieces are called, and where I can get new ones? These ones are pretty worn out and discolored. There is also one (center only) between the front bumper and the plastic grill.

In the picture I added (not my car by the way) it is the silver piece between the green of the rear fender and the bumper....

Any ideas?