I have an old BC Rich which previous to my owning has been totally beat up and the wiring hacked apart. Nobody has a correct wiring diagram for it since its not a USA model, and all of BC Rich's records for older korean basses were destroyed in a flood. I brought it to a guitar tech and he couldn't do anything with it. Its currently set up with two P-pickups connected to volume1, a pickup select, volume2, and a tone. Could I rewire it to include a switch that would bypass the tone control in favor of an active preamp?