A sample from the products for the Crankcase include: Plug Straigtscrew 132153510000, Case, Crank (l.h), Pin, Dowel, Stopper, Lever Change.
This Crankcase diagram displays the required parts for the Rd80 1982 12g Europe 2212g-300e1 Crankcase.
In this schematic the "Screw, Pan Head" is used most often.