Some items from this specific schematic: O-ring,15x2.5, Gasket,oil Pan (mca), Ring Oil 10mm, Gasket Set B (mca).
On this parts fiche the O-ring,15x2.5 is the most specified component.
The Cb1100rcii Australia England France Germany Netherlands Gasket Kit B consists of eighteen pieces with the Gasket Set B (mca) being the most expensive.