The twelve Z50j Monkey 1989 (k) Finland Cylinder component parts are all listed in this schematic.
Parts such as the Cylinder: Collar 14.8mm, Bolt Flang 6x20, Collar 9.5mm, Cylinder Comp. are included in the Z50j Monkey 1989 (k) Finland Cylinder parts fiche.
On this parts fiche the Pin,dowel,8x12 is the most specified component.