Re: gale 3hp
That is not actually a cylinder head, only a water cover. It was sealed at the factory with some unknown product and was not intended to be removed, so there is no gasket listed.
However, after 50 years, we have to do what we have to do, right? You can probably reseal it with some Aviation Permatex, the thick kind that comes in a toothpaste tube. And/or, make your own gasket. Or a combination of both.