On this parts fiche the Spring Brush is the most specified component.
Parts such as the E-10 Starting Motor: Washer,spg.,5mm, Washer,spring,6mm, Bolt,start.cover, Bolt, Flange,6x60 are included in the Cb400p 1981 (b) Police General Export E-10 Starting Motor parts fiche.
The Nut,thin 6mm is the lowest priced item on this E-10 Starting Motor schematic.