Parts such as the Crankshaft - Piston: Clip, Piston Pin, Piston (std.), Ring,piston 0.50, Ring,piston 1.00 are included in the Z50jf Monkey Germany Crankshaft - Piston parts fiche.
The Clip, Piston Pin is the cheapest item from this partsfiche.
Check out any of the thirty-three Crankshaft - Piston components enlisted.