Parts such as the Fuel Cock: Gasket (nas), Hose, Bolt(6x20), Spring are included in the Gs550ese 1984 (e) Usa (e03) Fuel Cock parts fiche.
With a quantity of five pieces, the Bolt is the most used part in the FUEL COCK diagram.
The Bolt(6x20) is the lowest priced item on this Fuel Cock schematic.