A sample from the products for the Frame Fittings(rear) include: Stay,rh, Bolt-flanged,6x12, Cover,rear Side,rh,f., Cover,under Seat,cnt,.
This schematic depicts all components used in the Kaf400-b8f Mule600 2008 Usa Frame Fittings(rear) partslist.
On this parts fiche the Rivet is the most specified component.