The 021-58119-01 Clip,nylon 14 is the most widely applied product in the 50EF 1989 OPTIONAL PARTS GAUGES & COMPONENT PARTS 1 ( five times ).
Some items from this specific schematic: Socket, Meter, Bulb (t6.5, 12v-1.7w), Bulb, Pilot (t6.5, 12v-1.7w), Screw,panh.tapping.
The component with the lowest price in the OPTIONAL PARTS GAUGES & COMPONENT PARTS 1 schematic is the Clamp (6e5).