This large wiper-type seal was used on used on 1951 Schult, 1951 Prairie Schooner and other trailers. It is inserted in the outer perimeter channel.
We suspect it is for windows made by Marvel Trailer Parts Company, but we could be wrong. If you have any documentation that could help with our investigation, let us know!
The U-shaped gasket used for the glazing is not currently available.
This gasket is sold by the foot.