The difference is in the corners. The upper corners are more squared off than the sedans.
Perhaps the rubber is flexable enough to used the sedan gasket.
The 1937-1938 Fisher "A" bodies were used on Chevrolet only.
How do I know this? In about 1982 went to a Central Meet in Iowa. There were two 1938 Cabs. parked side by side. We, a friend and I, noticed one had square corners on top, the other more rounded. The rounded job belonged to Harry Thompson , the guy that made the 1939 convertible. When we "confronted" him he admitted he made the 1938 convertible also.
Last edited by Chev Nut; 12/08/14 06:21 PM.