Thanks, DVM - well, strange goings on here. Here is what the switch positions are supposed to be:

1. neck & bridge
2. neck
3. neck & middle
4. middle
5. middle & bridge
6. bridge
7. Toggle switch bypasses the rotary switch and turns all 3 pickups on at once in series.

I tried all positions with the guitar plugged in, while tapping the pups with a screw driver.
In positions 1, 2 & 3 I got a 'pop' from the neck pup only (there is also no change in the sound/tone of the guitar between these positions)
In positions 4 & 5, nothing from any pup
In position 6, pops from middle and bridge pups only (thinner, brighter sound with less volume)
Blow switch on: pop from neck pup only (and same sound as positions 1, 2 &3 with blow switch off)


Measuring the resistance per your method, I got
Positions 1, 2 &3: 3.49
Positions 4 & 5: 0
Position 6: 1.78
Blow switch on: 3.50
So, all the pups seem to be alive, but something is messed up. I did look inside - nothing seems to be amiss there... at least not anything obvious.