RE: OS 40 SF
We don't have any list of parts that cross from one engine to another. You can try and see. You can also make a head gasket from .004"-.007" brass or aluminum shim stock. Before you do, though, please make sure you really still have the original cylinder head gasket. O.S. uses aluminum, and it looks like there's nothing there when you remove the cylinder head. If the groove it should be in is smooth, it's there. Look closely. You'll normally see some mold marks if the gasket isn't there. We remove them by carefully prying them up with the point of a #11 blade or a fine pin or needle.