To complement David's Vibra Artist thread (and because this is a new hosting site), here's the circuit diagram for the earlier Artist model. This uses a conventional ' one volume and tone per pickup' . The Artist guitar in my avatar had this circuit originally.
S1 is the pickup selector. The selections are:
1. Bridge pickup
2. All pickups (in parallel)
3. Fingerboard pickup
S2 is the Rhythm/Solo slide switch
Because the sliders of the pots connect to the pickups, there is virtually no interaction between controls (unlike the Vibra Artist). Being an early (very early) model, this guitar has the offset contour neck and originally had the 1/8" jack socket (which I still have stored away)
(one of the illustrations from my 1966 magazine article 'Electronics and the Electric Guitar)
Ray L