Weird stuff. I got bored tonight and did about 80% of it, but the 1's all look like 2's and vise-versa, the Hi/Lo pot wiring is something I haven't seen before, and it's unclear to me how the switching works (I assume the Dist/OD is a DPST on/on, and the Turbo is its own SPST, but if there's a demo of this circuit anywhere, that would help.
This is pretty close to the Prince of Tone circuit with an added input buffer....
Here's my take on it:
S1 is a DPDT On/On toggle switch. When S1A is closed you have Distortion, when S1B is closed you have Overdrive. If you used an On/Off/On toggle switch you would essentially have the "Boost' mode of the PoT when the switch is in the middle position.
Turbo is a SPST toggle switch. "Turbo" is active when the switch is open. You might get better results if you swapped the 220K and 1M resistor here.
The tone stack is just a typical fixed-mid Fender style tone stack.
I'm not a stripboard guy, but I could make up some PCBs for this.