Parts such as the Seat: Cushion,seat Bott, Seat Comp,*type2*, Nut,flange,6mm, Rubber,seal are included in the Pk50m Wallaroo 1993 (p) Italy / Sel Seat parts fiche.
Of all the components that make up this Seat the Nut,flange,6mm has the lowest price.
In this schematic the "Nut,flange,6mm" is used most often.