Success.
The reassembly went well enough. There were slight issues though. First was that reassembling the motor was a pain. You must somehow hold the brushes back so the rotor can be slipped in, then the rotor shaft must be clamped or somehow retained so when the magnetic other half of the motor is put in place the rotor doesn't pull itself out of its seat and pop off the brushes. This is made a little more harder by one wire harness that kept getting pinched between the two halves but once they were assembled a continuity check verified that we were good and it was screwed together.
The second issue is purely my mistake. While I was marking where on the shaft the various components were while they were removed, I didn't think about the vertical head positioning. It's kinda critical. Too high or too low and it would contact the drum. I also assume the recorded video would be offset form where it also would be. I totally should of checked the height with the calipers. The proper height is not listed in the service manual. After some playing I found that 7mm seemed to work. The head was not centered (and can't be because it sits underneath the mechanism and is mounted by an epoxy blob) but the assembly was evenly spaced between the top and bottom halves of the drum.
Reassembly of the top half was no problem as none of the precision adjustments had been touched. Simply bolt it back in, reset the video head brushes and you were done.
Finally the motor was connected to the bench supply and slowly brought up to a safe 10v while checking for excessive noise, vibration or other bad things. None were noted so the motor was reconnected to the machine, the bench supply set to 12.00v and the motor speed checked and adjusted.
The 5221a was rounding to the nearest 10 so I had to switch over to the 5334A to set the speed.
The camera now whines the high voltage at a different frequency, so presumably it now has a sync signal. Unfortunately there's still no picture. Once I'm done verifying the signal form the tape machine is good I'll move onto the camera.