That looks just like a pretty standard brushed motor, like you'd find on a router/drill (if you happen to have a broken router/drill, you could butcher the speed controller from them..)

I'm trying to remember if a basic PWM type speed controller will work with that.
Something tells me, the field windings still need full power, and you control speed through only regulating the armature power, but it's been that long since I've dealt with an AC brushed motor, I can't actually remember.