On this parts fiche the Pin,gearshift is the most specified component.
The most reasonably priced component used on the Cb250 Nighthawk 1991 (m) Canada / Kph Gearshift Drum is the Bolt,flange,6x20.
The eighteen Cb250 Nighthawk 1991 (m) Canada / Kph Gearshift Drum component parts are all listed in this schematic.