Hi Gordon,  I think those set-screws hold the sleeve bearings in
place.  I never really thought about it but that must be what they do.
I use motor oil like you get anywhere that you use for lubricating
motor bearings.  The one I get has a long flexible hose to get inside
where motor bearings often are.

I don't put too much on that felt especially, on the grand pianos as
they sit with the motor shaft vertical and the oil can run down the
shaft onto the belly cloth (or the carpet if no belly cloth is on
there) and into the motor on the top side.

Those motors are usually nice and quiet.  Maybe the washer on the down
side is worn or something making it noisy.  If runs quieter with the
the motor shaft horizontal that may be the case.  I usually send the
motors out for cleaning and lead cord replacement.

Ben Gottfried - Ben's Player Piano Service
Richfield Springs, New York
http://www.bensplayerservice.com/