The lowest price component in this Left Crankcase Cover / Oil Pump parts-list fiche is the Screw,cross 6x35.
Some items from this specific schematic: O.ring ,6.9x1.5, Sw Assy, Oil Press, O-ring, O-ring,15x2.5.
The Screw,cross 6x35 is the most widely applied product in the CB350F FOUR 1972 USA LEFT CRANKCASE COVER / OIL PUMP ( four times ).