A repair is coming in.

Burns Vista Bass.
3 Tri-Sonic low impedance pickups (5,2 ohm)
4 Pos (Contra bass, bass, treble, Wild dog)
volum and tone
2 transformers.

Have a customer with this bass. It's got all pickups (low imp) and transformers.
But wires have been moved. There are two or three resistors in there now, but that might been added when someone "modded" it.
Have googled to find info, especially wiring or how the switch function.
Found similarities of 3 pickups Burns Jazz Bass, and/or Bison...
Does anyone here know anything about these?
Or where to find info...