On my street car I used a trick to run the wire from the horn button on the steering wheel down the inside of the column: I used a 1/4" phone plug and jack in the hub to make a removable connection. The plug was mounted in the center of the steering wheel and, when installed, it mated with a phone jack that I mounted in the center of the steering column. I ran the wires through the column down to a hole in the side where it looped around a couple of times so that the wires were not pulled tight at the stops. If you need two wires plus ground, use a stereo 1/4" phone plug & jack.
The coaxial arrangement allows the steering wheel to be put on in any orientation.
Bin looking at your system for a bit now, thanks Neil. My steering shaft is solid and I would have to get the wires through the QR and would have to drill down about 3 inches and exit the shaft to a coil or a form of clock spring, a lot of work. Still thinking?????????