Re: 1957 Gale Buccaneer 5hp fuel pump repair kit?
If it has the original fuel pump, it has a double layer diaphragm, with the metal support riveted to the center of it. That diaphragm and related parts has been not available for umpteen years. Having said that, I have used the 393103 kit (18-7820). The only thing in it that you can use is the diaphragm and plastic support. You have to "move" one of the lower corner holes upward 1/2 hole width. But you are SOL if you need the gasket unless you think you can make one.
Personally, I think the best cure is to just slap on a new 18-7350 fuel pump from here at iboats.