Late 1960s Nylon top block that goes in the rail

Greetings. We do carry a selection of nylon pivot brackets on the web site, such as our 21-203 and 21-204, but I could not find one exactly like yours. See if you can adapt the ones we carry. Also do you know the manufacture of your bi-fold door? See if there is a label on the back side of your door. That might help narrow it down.