We need the schematic.
Anyway, this pedal is just a sort of multi Tube Screamer: the switch changes some parts to get every version. Sometime those parts are the diodes, or some resisistors, or caps, or pots or a lot of different parts.
It's kind of hard to me imagine how we could make a rotary switch like that. Or maybe that switch is very very simple and not so close to every schematic, so basically the schematic is pretty the same for every version and it changes just few parts.
I build pedals