On this parts fiche the Damper,rr Hub Shock is the most specified component.
The most reasonably priced component used on the Kv100-a7 1976 Usa California Rear Hub/brake/chain ('74-'75) is the Nut,10mm.
Some items from this specific schematic: Cam-brake, Rear Sprocket 42t, Cam-brake, Sleeve,rr Hub Couplin.