The Ar80a1 1982 Usa Oil Tank consists of six pieces with the Tank-oil being the most expensive.
The lowest price component in this Oil Tank parts-list fiche is the Washer-spring,6mm.
Some items from this specific schematic: Washer-spring,6mm, Washer,6.5x20x1.6, Cap-oil,tank, Bolt Upset,6x16.