That reminds me of a guy I met back in the early 1990's at a sidecar rally in PA. Forget the bike it was one of the typical sport bikes at the time and it had a Vetter sidecar attached. Guy was in wheel chair and was camping in a tent at the rally.That motorcycle reminded me of another one I saw. I was in a Walmart once and while I was shopping , I had noticed this guy in a wheelchair who was shopping. He looked to be in his forties and his wheel chair was this lightweight collapsible model. Later as I was walking to my car, I saw him in the parking lot. He had a Honda VTX1800 with a sidecar. It had been modified so that the front brake lever actuated both, front and rear brakes, and the shifter had been ran up to the handlebars , operated by a cable, and attached to a little stick shift.
I knew all of this because it caught my eye before I went into the store and I went over to check it out.
Anyways, he rolled up to it, and deftly pulled himself up onto the seat, then he reached down and folded the wheelchair and tossed it in the side car. I swear I felt like applauding the guy as he rode off!
Don't remember the brake set-up he had but the shifting was a simple rod attached to the foot shifter and run up to the side of the fuel tank with a bracket to hold it in place. It had a ring at the top and to shift he would just pull up or push down on the rod. If I recall correctly he was up in PA from Florida!
Another sidecar outfit I saw was set up to let the guy roll his wheel chair up a ramp right into the sidecar. He had removed the handle bars and controls from the bike and mounted them over on the front of the sidecar and had a tie-rod going from the sidecar over to the bike. Can't recall about the shifting but it may have been one of those automatic transmission Hondas, maybe a CB750A?