Here's that motor, just reassembled. The similarities are pretty obvious, especially the way the brushes are mounted. This one is a three pole motor, but I've seen a seven pole version before. I'm not completely confident it's a Pittman, but it probably is. It was pretty finicky while reassembling - if I tightened it the wrong way, the armature bound up. I'm pretty sure the insulated sections on the two studs that the brushes are on are to blame, they may have been crushed over time and so will skew the top plate when tightened. Anyway, I managed to get it spinning freely after messing with it for a while.
