Parts such as the Gear Shifting: Spring, Bolt(6x18.3), Stopper,gear Shift Cam Neutral, Oil Seal are included in the Rm50 1979 (n) Usa (e03) Gear Shifting parts fiche.
On this parts fiche the Pin(4x15.8) is the most specified component.
The Pin(4x15.8) is the lowest priced item on this Gear Shifting schematic.