Does anyone know what the black 'stuff' is on the window frame area? It looks like black rubber gone hard or it could be some sort of black caulking that also went hard. It is kind of like bakelite, hard and brittle. Whatever it is, it provide works as a 'spacer' to bring the aluminum window frame flush with the fiberglass door as viewed from the outside. It probably also provide a water seal.
Tom
74 TCS - 4605R