Parts such as the Cylinder Head Cover: Cover,tappet Adj., Lifter Comp Valve, Bolt,flange,7x50, Case,tach.gear are included in the Cb250rs 1982 (c) England Cylinder Head Cover parts fiche.
With four applications this Bolt,flange,6x20 is the most specified part.
The Washer Seal, 6mm is the lowest priced item on this Cylinder Head Cover schematic.