Rear window gasket, vinyl top versus non vinyl differences?

If I had to guess, I would say that it must seal over the vinyl top material and has a wider slot and/or perhaps has some micro ridges or something to seal onto the texture of the vinyl. Probably worth the extra money if you have a vinyl top. Very interesting though. I have been trying to find the chrome for my 71 Demon so that I could install a vinyl and this is something I had not thought much about.