Parts such as the Rear Fork/chain Case: Bolt,fork Pivot, Chain,drive Did42, Bolt,flange,6mm, Joint,drive Chain are included in the Z50j Monkey 1991 (m) Finland Mk Rear Fork/chain Case parts fiche.
With two applications this Bush,rabber,fork is the most specified part.
The most reasonably priced component used on the Z50j Monkey 1991 (m) Finland Mk Rear Fork/chain Case is the Joint,drive Chain.