Parts such as the Crankcase Lh Cover: Screw (6x35), Screw, Plug (14x12), Nipple are included in the Gs425 1979 (n) Usa (e03) Crankcase Lh Cover parts fiche.
The most expensive part in this assembly is the Cover,engine Sprocket.
In this schematic the "Screw (6x35)" is used most often.