On this parts fiche the Washer,10mm is the most specified component.
Parts such as the Oil Tank / Rear Carrier: Label, Oil Caution, Nut,hex.,cap,10mm, Clip B8,tube, Clip Breather Tube are included in the Nc50 Express 1983 (d) Usa Oil Tank / Rear Carrier parts fiche.
The Oil Tank / Rear Carrier is made up of components including this Carrier, Luggage which is the most expensive.