noisy Electro-Craft E543 servomotor

I bought a used Electro-Craft E453 brush-type servo on the weekend
from a local surplus store. When powered up (at up to 28 volts) it
made various high pitched noises which sounded like they might be bad
bearings. When I looked at the brushes I noted that they were mounted
about 30 degrees off the motor axis. (Any other brushes I have seen
were in line with the axis). The wear pattern on one brush looked odd
so I scraped away some of the odd corners. This greatly reduced the
noise, so I now assume it's not bearings causing the noise. The noise
continued to reduce as I ran the motor.

Should the brushes be oriented this way? There are what look like
small hex set screws next to each brush holder, do these permit
adjustment of the brush position? And where might I find replacement
brushes?

Also the motor note is somewhat uneven though this has improved with
the brush change. Is this likely the brushes, or? The current
consumption of this device is in line with what Electronics Goldmine
describes for this motor (about 240 ma no load). (I got mine for C$15
here in Toronto)

Finally, does anyone have specs for this motor? (I know it has been
mentioned in a couple of provious posts.)

Grant