Parts such as the Handle Switch - Lever: Washer,spring, Lever Holder Assy (r.h), Holder, Lever, Screw, Pan Head (5y1) are included in the Xt550 Dual Purpose 1983 (d) Usa Handle Switch - Lever parts fiche.
The Handle Switch - Lever assembly is constructed from several parts from which the Switch, Handle 3 is the most expensive.
In this schematic the "Screw, Panhead" is used most often.