The six Gs450ex 1982 (z) Usa (e03) Handlebar (gs450st component parts are all listed in this schematic.
A sample from the products for the Handlebar (gs450st include: Cap(od:14), Clamp, Handlebar, Mirror Assembly,right.
The Gs450ex 1982 (z) Usa (e03) Handlebar (gs450st consists of six pieces with the Mirror Assembly,right being the most expensive.