Not familiar with the Mira, pictures of the control cavity would help.
It would all need to be rewired to change which coils are selected.
You would need to wire one coil inside out (bridge), and the neck outside in.
If I was wiring it, I would forget about the phase switch wiring to start with, until I had the split figured out and working.
A wiring diagram you can mark up will also help you figure it out.
Another simple option, is to turn the pickups around in the pickup rings.