On this parts fiche the Seal,valve Stem is the most specified component.
The Gasket Kit A assembly is constructed from several parts from which the Gasket Kit A (nas) is the most expensive.
The most reasonably priced component used on the Gl1500se Goldwing Special Edition 1992 (n) Belgium / Kph Gasket Kit A is the O-ring,18.3x2.3.