Parts such as the Cylinder Block: Boss, Oil Filter, Band,wire, Sw.assy Oil Press, Clip,tube are included in the Gl1800a Goldwing 2005 (5) Australia Cylinder Block parts fiche.
On this parts fiche the Clip,tube is the most specified component.
The most reasonably priced component used on the Gl1800a Goldwing 2005 (5) Australia Cylinder Block is the Tube Ai B.