How?
The tone pot is used in a two-terminal rheostat configuration. It is just a variable resistor.
The volume pot is used in a three-terminal potentiometric (ratiometric) configuration. It is just two variable resistors, one from the input terminal to the wiper and one from the wiper to the grounded terminal.
I would buy three fixed resistors and share the same tone cap since caps have a +/- 20% tolerance. I would use a DPDT switch. A clever sort might use a DPDT push pull pot.
Yep, you betcha for the volume pot.
Now, how would one do this? Since the guitar is single coil based, the pickups likely have a DC resistance of 5 to 7 KOhms. The volume pot is likely 250 KOhms
nominally.
If it's 5K and 250K, with the volume control at "10" (full-on) and only one pickup selected, the resistance measured at the output jack, from tip to sleeve, will be 4.9K.
Let's re-assume that the pickup is 5K and the pot has a +/- 20% tolerance. At 200K we would measure 4.88K and at 300K we would measure 4.92K.
Hmmm, these are all around 2% less than the pickup alone would measure for a pickup of 5K, and 4% for a pickup of 10K.
That being said, one can safely assume that the maximum effect of the volume pot in parallel with a pickup will be about 2 - 4% maximum'ish.
procedureRemove the Tele control plate.
Set the volume control at "10" (full-on) and with only one pickup selected, measure the resistance at the output jack. Post it (R10). This is 2 - 4% less than the resistance of the pickup alone.
Set the volume control to the exact spot that you like it and with only one pickup selected, measure the resistance at the output jack. Post it (Rbot).
Also measure the resistance from the wiper to the input terminal on the volume pot. Post it (Rtop).
Measure the resistance of the tone pot when it is set to the exact spot that you like it. Post it (Rtone). This is the value for the fixed tone resistor as there is no DC coupling in a high-cut tone control that will affect the reading.
/procedureAfter you post these I can do a few quick calculations.
R10 = Rpu || (RVtop + RVbot)
Rbot = RVbot || (RVtop + Rpu)
Rtop = RVtop || (RVbot + Rpu)
No, only to humans. Audiophiles will assure you that only oxygen-free hydrogenated vegetable oil-based resistors costing at least $60 each can possibly sound the same.
No, you'll be forced to settle for being within 1% of the measured value (of course, your meter likely has a 1 - 2% accuracy error).
Since you likely might want the volume and tone controls to have no effect when the "special mode" is selected, we would want to switch them out of circuit, and the new components in circuit, and sharing the same tone control cap might help eliminate any popping.
If this is true, let us know and I'll post a diagram.