Quick update...
I made a change of brushes as initially suggested by Cheater (and a couple of additional mods below) and broke it in as I normally do (short water break-in, followed by thorough cleaning and then dry run-in on my laboratory power supply), allowing the brushes to seat well against the comm. I can tell it worked because the comm looks almost clean, only a few light streaks. The motor does not run as hot, but I noticed it seems to draw slightly more amperage than before at the same voltage. You guys who understand conductivity better than me probably know the reason. When viewing from the endbell, the arm turns ccw.
A few minor alterations, but not a full "blueprinting":
As mentioned before, new Gold Dust brushes
Lighter springs -- adjusted slightly for proper contact
Although I didn't re-glue the can bushings, I disassembled the motor and inspected. Bushings appeared to be very well aligned already and seated in place tightly.
I added spacers to center armature in magnetic field and reduce back and forth movement as power is applied.
All in all, the motor runs smoothly and much cooler. It was otherwise straight out of the bag, although I bought it sometime ago. As fast as it feels, I might have to install it on a new chassis and get it ready for weekly racing.
Thanks for all the insights. The responses only prove I still have much to learn.
jb