I asked the seller about the three extra mini-switches, here's his answer:
"Beats me, I never played it, never set it up, never turned a screw. I never touched the truss rods, but both covers have Model 4080. I never cleaned anything, never even took the fuzz balls and goobers out of the case. I showed it to my guitar player once back in 2001, and saw death in his eyes. The kind of look that said if I ever dared to walk on stage with that thing, he would beat me over the head with it. But it is cool! I can plug it in and find out, at least in mono. I should have bought the Ric-O-Sound rig also, back then they were everwhere for $75 NOS. Usually when I bought a new bass I would polish the frets with Mothers, string it with GHS Boomers, adjust the truss rods to wire straight the neck to the strings, check for buzz and dead spots, then set the string heights, adjust the pickup heights (level is important), set the intonation, polish the metal parts and the guitar, then try it out. But I still remember the look in his eyes, like Dirty Harry. I quietly put it away. One thing led to another and here we are. I never got to first base. (bass?) The pickups are single coils, so they are not taps. Probably kills and crossovers for mono/stereo, bass/guitar. No active preamps. I really do not know, but for that kind of money I will find out. I really should set it up for the new owner, I'm good at the details. GL"