The Washer Seal, 6mm is the cheapest item from this partsfiche.
Some items from this specific schematic: Washer Seal, 6mm, Bolt,plug Drain 14mm, Bolt,flange, 6x32, Pin Cotter 3.0mm.
With all the components that make up the CB750K 750 FOUR K 1979 (Z) USA OIL FILTER / OIL PAN assembly. The Bolt,flange,6x28 is the most frequently specified with fourteen applications.