These are the original tire sizes for the 1st gen 1975-1979 Goldwing (GL1000) per the factory manual, Dennis Kirk, and Steve Saunders' websites:
Front: 3.50 x 19 (OEM)...matches to: 100/90 x 19
Rear: 4.50 x 17 (OEM)...matches to: 130/90 x 17
GrumpyGrizzly,
I also found a side fuel tank for my GL1000. My 2 (1.1 gallon) fuel tanks mount in place of the side cover similar to yours, so I have the OEM under seat 5 gallon tank as well as 2.2 more gallons to extend my ride. My tanks required extra fuel lines that attach to the main line. I...