In this schematic the "Screw-pan-cros" is used most often.
The lowest price component in this Taillight(s) parts-list fiche is the Screw-pan-cros,6x20,b.
Some items from this specific schematic: Spacer,4.5x6.5x10, Bulb,12v 32/3cp, Cover,tail Lamp, Lens,tail Lamp.