Is there a two part urethane rubber compound to pour your own rubber parts? Or a company that could do it small quantity reasonable?
The rear seat back on my wagon has 5/8” x 1” x 3/4” rubber bumpers it rests on in the upright position. They are hard as rocks from age. Not something I will find reproduced most likely........ They have two counter-bored holes for mounting them and the seat release spring clip, with two #8 sheet metal screws.