I don't own any G&L guitars, but have wired several guitars with separate bass & treble cut controls.
Not exactly the same topology as yours- but close.
Here are some suggestions:
1) To warm icepick pickups, try a ~1nF "defroster" cap across the treble control.
See C3 in G&L's S-500 schematic:
2) Unless you have an actual reason to cut the bass (e.g. muddy neck pickup, farty overdrive, jazz box feeding back), leave the bass cut control on 10 (i.e. shunting the bass-block cap).