On this parts fiche the Plug.6mm Hex. is the most specified component.
The Rubber, Mount is the cheapest item from this partsfiche.
Parts such as the Cylinder Head Cover: Socket Bolt,6x18, Bolt.special 6x72, Rubber, Mount, Cover Comp,r Cyln are included in the Gl1500 Goldwing 1990 (l) Italy / Kph Cylinder Head Cover parts fiche.