I have a 1975 H27 it has 8 alumium framed deadlights (non opening windows) I am about to begin rebuilding them, new plastic and seals. The window has a rubber seal on the out side that wedges into the frame. It is about 1/4 thick x 5/8 wide and goes around the entire window. Does anyone know of replacement material? I've tried Mark Plastics but no luck. Thanks