Some items from this specific schematic: Ring,stopper C, Seat,spring, Spg,rr,cushion, Bush,upper Rubber.
The lowest price component in this F-20 Rear Cushion parts-list fiche is the Bolt, Flange,6x12.
The sixteen Xr500 1979 (z) Canada F-20 Rear Cushion component parts are all listed in this schematic.