This Seat Comp.,double is the most expensive of the items that make up this Seat/seat Cowl assembly.
The lowest price component in this Seat/seat Cowl parts-list fiche is the Screw,tapping,4x1.
Some items from this specific schematic: Cover B,rr.grip, Cowl S*pb-161c-u*, Bolt,flange,8x16, Screw,tapping,4x1.