Tim says I have a memory like an elephant (that's a compliment, right?) and I have a few recollections about the '75 Goldwings.
The Goldwing was originally designed as the replacement for the CB750 Honda and was to be the top of the line Honda Sport Bike, so no bags, no windshield, no touring pegs or backrests.
Apparently, there was such a rebellion among the first dealers and distributors who saw the prototype 'Wings, that Honda upper management was forced to continue the SOHC 750 until '79, when the DOHC 750's came out.
By that time, it was becoming obvious to even Honda that the Goldwing was a superb touring bike and as a sport bike, "not so much" and by the '80's, had started to come out with their own accessories and then later, made most of them basic to the bike.
That didn't stop certain Honda factions from trying to prove the Leadwing could hustle, though. Nikko Bakker (in Holland and still in business) built an endurance racer for Honda Europe in '76 or '77; special frame and suspension, wheels, bodywork, heavily breathed on motor - in essence, a purpose-built race bike powered by the flat four. I had a photo of the bike at Bol'd'Or, cranked over and just touching the right side cam cover, going through a corner. The cambelt cover on the front of the motor was missing - I found out later that the belts overheated at racing rpm's and removing the cover helped a lot.
Neat bike, would like to use the drivetrain from one in a Morgan-style 3 wheeler, but could never imagine trying to hustle one through a corner with clip-ons.
Pat