The reality is, MOST of these gaskets are "stock profiles", and with a bit of ingenuity and patience, you can find and use something designed for something else.
The rear quarter window gaskets were cut out of my 1964 Plymouth wagon by the body shop. At that time, they were NOT available anywhere! I called in our local glass installer who felt he could come up with something that would work, even if it weren't a molded gasket "ring" like the OEM. I left him with the task!
About two weeks later, I get a call from the body shop telling me a box had arrived in my name on it for the car. The next day, the glass guy installed the quarter windows, and unless you were standing arms-length or closer to the car, you'd never know they weren't factory correct!
I asked him how he found the gaskets, and he replied that it turns out the windshield gasket for a late-model Caterpillar with a cab was actually the correct profile for the 1964 Plymouth, so that's what he used!
