Hi, from what I found and your values are supporting my theory it should be like this:
Switch 1 (humbucker up, coil split down, unless ....)
Switch 2 (in forward position it changes both humbuckers into parallel mode - humbuckers are series by default .... Switch 1 then doesnt work - I dont think I hear a different sound when I change Switch 1)
And the resistor math works and sound too.
So starting from Switch 1 Up, Switch 2 backwards -> humbuckers (all in kOhm, basic resistor rules)
Neck 9.5
Bridge 13.9
Middle = 1 / (1 / 9.5 + 1 / 13.9) = 5.62 ~= 5.8 -> two parallel humbuckers
Then Switch 1 Down (coil split), Switch 2 backwards -> single coils (assuming both coils in humbucker have the same resistance, so the hum canceling works)
Neck 9.5 / 2 = 4.75 ~= 4.8
Bridge 13.8 / 2 = 6.9 ~= 7
Middle 1 / (1 / 4.8 + 1 / 7) = 2.85 ~= 2.9 -> two parralel single coils (the hum kinda throws me off on this one, that means the pickups are same polarity same winding and I dont think it is the thin phase out sound)
So then we use the Switch 2 in forward position, the sound changes to something like Stratocaster in 2 or 4 positions and I dont think I hear change when switching the Switch 1 at all So we take both single coils together in parallel:
Neck 1 / (1 / 4.8 + 1 / 4.
= 2.4 (checks)
Bridge = 1 / (1 / 7 + 1 / 7) = 3.5 ~= 3.6
Middle = 1 / ( 1 / 2.4 + 1 / 3.6) = 1.44 ~= 1.5 (all 4 coils in parallel):
Hum checks and I find it logical to make, when you engage Switch 2 to forward position, it will use different path that omits Switch 1. So judging by the math Switch 2 works on pickups parallel / series ,not on middle position. And if you use series (humbucker pickup), then you output will rise (adding), in series the output will average. And the volume leves are only higher on Switch 1 up, Switch 2 backwards. Only weird thing is that hum in coil split in middle position, switch 2 backwards, but then you realize that those two humbuckers are reversed (as it should be), and that the coils split works on both pickups the same way (it is easier to make), so you either get inner or outer coils in split. Judging by the metal test on pickups they are outer coils, but it is in metal casing, hard to be sure and I dont feel like digging deeper.
Anyways the guitar is very versatile in my opinion. It has 2 humbuckers sound, it can sound like jaguar in coil split or in parallel mode like strat in positions 2 and 4. That middle position with hum is kinda like Telecaster middle (but Telecasters are RWRP wound nowadays without hum). I think its nice and I love that guitar. And I think it can be modded easily and make those switches do something else (maybe Quadbucker ? both humbuckers in series, but the it could be too muddy), those switches are much convinient than push/pulls.
But at the end, I did not look into wires, so I can be wrong
