Pole Changing Motors?

Hey all,

I am considering purchasing a Deckel mill on which the controller is
toast (actually almost new, but still toast somehow).
The main spindle motor is listed as a 6hp "Pole Changing motor with
brake" in the brochure, which is all the information I have on it.
Since I'm utterly stupid when it comes to motors and motor theory, I
am wondering what such a motor might be driven by? AC, DC, 1 or 3
phase, or perhaps step/direction?
My concern is being able to bypass the original electronics of the
machine and still gain control of this motor.
Unfortunately I don't have access to the machine before I buy it and
with all this stepper/servo stuff in my head, "pole changing with
brake" sounded familiar. Could this be a 6HP stepper, or can you
brake (hold) an AC or DC motor electrically?

What is the "usual" current or signal type for a braking, pole
changing motor of this HP?

Many Thanks
Sean