I'm pretty sure I'm right as the resistance reading would be wrong for anything else. Is there anything on the back of the pickup that gives a clue to its origin or do you know what guitar it was taken from?
You could simply hold the wires against a lead plugged into an amp. If I'm correct, then hold the bare twisted wires against the sleeve of the jack plug and the black wire against the tip of the jack, and you should get a loud knock when you tap the pole-pieces of both coils with a screwdriver, Then hold the red/white wires against the tip and you should get a slightly thinner loud noise from one of the coil's pole-pieces, and a much quieter one from the other coil (which would just be mechanically transmitted vibration to the other coil).
You could also try holding it just above a guitar's strings which should give you more of an idea of the difference between the full humbucker and tapped coil sounds.