Parts such as the Repair Kit 1: Screw, Adjust, O-ring (647), Oil Seal (18x30x5-663), O-ring (371) are included in the Cv55e 1989 Repair Kit 1 parts fiche.
With two applications this Gasket is the most specified part.
Of all the components used in this assembly the Gasket Kit For Power Head is the most expensive.