Some items from this specific schematic: O Ring(d:1.3,id:9.6), Washer(8x13.7x1), Washer, Union.
On this parts fiche the Gasket(6.2x11x1).2 (nas) is the most specified component.
The lowest price component in this Oil Pump parts-list fiche is the Gasket(6.2x11x1).2 (nas).