I left the tuning mechanism alone so the kids can sill push the preset buttons and watch the needle move all day long. But you could build a balance/fader knob on that side if you wanted using the same technique and simply wiring one pot inversely as is also
explained here.
I installed a new bulb while I was in there (also put all new bulbs in the rest of the dash).
This set-up would work for any audio device that is designed to be run through AUX inputs in a deck and has its own control interface.
Here it is installed. The faceplate is pretty thin and could be mounted anywhere, but it's going here for now (hot glued on so it's easily reversible).
Next install; my new covered fiberglass kick panels thanks to
this FAQ 
