On this parts fiche the Washer(10x15x1.5) is the most specified component.
Some items from this specific schematic: Bolt, Cylinder Assy,fr Master, Cylinder Assy,fr Master, Hose Comp,front Brake.
The most reasonably priced component used on the Rm250 1999 (x) Usa (e03) Front Master Cylinder (model T/v/w) is the Screw.