The Primary Shaft assembly is constructed from several parts from which the Shaft,primary is the most expensive.
The most reasonably priced component used on the Cb750f 1983 (d) Italy Primary Shaft is the Washer,plain, 6mm.
Some items from this specific schematic: Spg,prim.tension., Washer,8.2mm, Pin, Knock, 3x5.2, Chain,primary..