I am attempting to bring a 7 HP 1970 Eska (mod 217-58531, ser. no. 103670) back into running condition. I disassembled the powerhead just far enough to clean out the cooling water channels, but was unable to save the gasket in the process. Does anyone know of a source for such gaskets. I tried the Sears parts site, but if it was there, I missed it. Any help would be appreciated.