For '65-'66 cars, regarding the vent windows. When I separated the glass from the frame, there was some black weatherstrip like stuff that holds the glass in or insulates it against the metal frame. I cannot find that in any catalog, and mine crumbled out. Is it just black silicon from a tube? It looked to be an insert since it was so uniform. I am not talking about the vent window weatherstrip, I'm talking about the stuff that separates the actual piece of glass from the thin frame around the glass. Thanks guys!