On this parts fiche the Shoe Comp,rear Br (mca) is the most specified component.
A sample from the products for the Rear Brake Panel (xl600vh/vj/vk/vl) include: Nut,flange,6mm, Axle,rr.wheel, Seat,fr.brk.cam, Shoe Set,brake (nas).
The fifteen Xl600v Transalp 1989 (k) Switzerland Rear Brake Panel (xl600vh/vj/vk/vl) component parts are all listed in this schematic.