Parts such as the Tail Lamp: Grommet, Washer(6.5x20x1.2), Lens, Washer are included in the Ds80 1985 (f) Tail Lamp parts fiche.
The most reasonably priced component used on the Ds80 1985 (f) Tail Lamp is the Bolt.
The thirteen Ds80 1985 (f) Tail Lamp component parts are all listed in this schematic.