I have found out the jumper cables are merely shielded wire with 3.5 mm aka 1/8" mono phone plugs on each end. So, I'll make some up, plug them in, and see what happens.

I had noticed that this Pioneer 6 disc magazine is identical to the Onkyo mags on some of their older CD players. That led me to thing that maybe they were actually the same under the skin. But I have found out that the mechanism was actually made by Phillips. The same mechanism and magazines are used by Pioneer, Onkyo, Phillips, Hitachi, Realistic/Optimus, and several other brands.

Will see what happens.