On this parts fiche the Screw 6x12 is the most specified component.
This schematic depicts all components used in the Rm85 2006 (k6) Usa (e03) Fuel Tank (model K6) partslist.
A sample from the products for the Fuel Tank (model K6) include: Cap,fuel Tank Filler, Tank,fuel(yellow), Screw, Hook,seat Fr.