The Bolt-upset-wsp is the lowest priced item on this Seat schematic.
This SEAT assembly utilises six Bolt-socket,6x30,blac(s) - the highest specified component.
Parts such as the Seat: Plug, Stay,carrier,lh,f.bla, Grommet, Nut,6mm,black are included in the Z750p3 1984 United Kingdom Fr Seat parts fiche.