On this parts fiche the Lock,washer Tank is the most specified component.
A sample from the products for the Taillight (b,d1,d2,de,f,u) include: Washer,spg.,5mm, Lens,tail Light, Packing Tail Base, Screw,cross 4x50.
The Bolt,hex., 6x16 is the lowest priced item on this Taillight (b,d1,d2,de,f,u) schematic.