entwistle dark star

[WeirdBits]

For series/parallel switching on humbuckers you will need one push/pull pot per pickup, as you need both poles (sets of contacts) on the pot's switch to do it. If it was just coil splitting you can do two pickups with one push/pull.

You can get 4-pole mini-switches which would allow you to do series/parallel switching on both pickups at once using a single switch, but two push/pulls are probably easier, cheaper and more versatile.

Edit: Entwistle humbucker diagram shows the series/parallel wiring with their colours.