On this parts fiche the Bolt is the most specified component.
The most reasonably priced component used on the Gs1000g 1980 (t) General Export (e01) Rear Combination Lamp is the Bolt.
Parts such as the Rear Combination Lamp: Lock Washer, Spacer(6.1x9x7.5), Bracket, Licence Plate, Washer are included in the Gs1000g 1980 (t) General Export (e01) Rear Combination Lamp parts fiche.