I talked with the ebay seller. He copied a tank from a 1941 senior. Books show this is a 20 gallon tank. My need is for a 1940 senior, book shows should be 21 gallons. The one gallon should not make much difference, I don't think. My main concern is the placement and angle of filler neck. On my 1940 the opening between the frame members gives only about an inch clearance top and bottom for the neck. Might anyone know if the frame for a 1940 super, and a 1941 super are the same where the filler neck goes through it? Thanks Todd