@Baloney Balderdash - I must say, Tim is a genius when it comes to fabricating for basses without pickguards.
He’s helped me with some previously.
you can make a paper template (or card) and he can work from that.
No it’s volume/blend/bass/treble
TRB has either a mid sweep or a 3 notch preset mid Control (depending on era) - also some TRB’s had a piezo control too.