Parts such as the Headlamp: Screw, Washer, Washer,lock, Rim are included in the Gs1000g 1981 (x) General Export (e01) Headlamp parts fiche.
The eighteen Gs1000g 1981 (x) General Export (e01) Headlamp component parts are all listed in this schematic.
The Screw is the cheapest item from this partsfiche.