Parts such as the Seat: Bolt,socket,8x50, Grip,r.pas*type1*, Grip,r.pas*type2*, Grip,l.pas*type1* are included in the Gl1500 Goldwing 1988 (j) England / Mkh Seat parts fiche.
Check out any of the seven Seat components enlisted.
The Bolt,socket,8x50 is the cheapest item from this partsfiche.