The most reasonably priced component used on the Vz800 1997 (v) (e02 E04 E17 E18 E22 E24 E25 E34) / P37 Front Caliper is the Bolt.
Some items from this specific schematic: Bolt, Pin,pad, Piston Set, Clip,pad Pin.
On this parts fiche the Bolt is the most specified component.