I have a 1957 Sea King 12hp (GG8971B) and I'm rebuilding the fuel pump. Everything in the pump looks like it's in great shape with one exception. One of the plastic discs (OMC 303643) that combines with a spring to make a check valve is ruined. I tried to make a new one, but I can't find a suitable material. I went online to track one down, but all I could find was OMC 305654. The discs I have are just little round ones, but this other part has a cross on both sides of the disc. It appears one is to align it with the spring and the other to align it with the valve housing. (I kept wondering what kept mine in line, other the gasket between the halves of the housing.) Anyway, I can't find anywhere that gives a dimension to see if these new discs will fit with my pump or not. I realize that there are a few replacement pumps out there and I might end up going that route, but I'd like to try and keep as many original parts on this motor as I can. So if anyone has any input on whether or not these other discs might fit my fuel pump I would really appreciate it. Thanks a lot.