87 Elky, need to replace that "riveted donut shape" part on door windows that keeps windows from raddling when completely up. Saw this part on YouTube video for "window adjustments" for 87 gbody (it was a Monty I believe???) As window goes up, it slides onto a pin, locking window into place. Both mine r broke and want to replace....what r they called, where can I get them, and who/how do I get installed??? Anybody know what I'm referring to???