At this point I took the switch that was supposed to select bass pickups (Neck, bridge, or both) and turned that into a selector switch. Honestly, I've been playing bass for years and I don't recall ever seeing a bass with a selector switch. That's what volume knobs are for! (Or balance if you play an Ibanez).
It had two volume (one for bass, one for guitar) and two tone knobs.
I'm putting in four dual pots (Warmoth is the only place selling these that I could find, oddly enough) and each pickup will have its own tone and volume. I was orignally thinking of only one tone control for the bass, but I didn't want to break up the symmetry.
I'm also putting in a second 'stereo' jack, where the two channels will be one for Guitar and one for Bass, so the ability to have separate amps exist. I will have to put in a quick blow fuse, in case someone plugs into both and then shorts everything out by putting the selector in the wrong position.