Problem(s) Encountered:

Determined today that the issue with the rotator has something to do with the failsafe brake. Removed it from the motor assembly and was able to use the rotator without any issues.

Solution:

Found after digging a bit deeper today that the brake unit was not getting its required voltage to disengage prior to rotation demand.  Replaced a relay (Dynatec D2101) in the rotator control box with a spare (a miracle of the OSU locker: exactly one spare relay!), solving the problem.  System is back together again.
On the bench, I took apart the dead relay and found both onboard fuses to be dead.  I ordered some spare fuses.  Hopefully that will get that relay back in service as it appears these relays are no longer stocked.  

Update:  spare fuses just blew as well.  Looks like a suitable spare is a CBC-801 plug-in octal socket power supply.