Re Fox Morrey's posting -- I'm also surprised that a 1916 piano
wouldn't have a sustain pneumatic, but I assume your tracker bar has
no hole for it and no pneumatic connected to the pedal linkage?  That
is, you've checked that it just isn't working?  And there is no button
to manually add sustain?

To shine up the brass tracker bar without clogging, my trick is to use
plain old Brasso, but to hold the can upside down on the rag for a long
time to let the rag absorb plenty of liquid but no more of the powdery
"gunk".  The gunk will be confined to a circle where the rag covered
the can's hole, but around the circle the rag will be wet with the
liquid chemicals that clean the metal.  Use that part of the rag.  And
of course "forget" to shake the can first.

Yep, sounds like your tempo regulator isn't regulating fully.

And you do have roll slippage diagnosed correctly, and the less braking
the better.

As for reroll speed, the regulator should still be "in the circuit"
during reroll, and only the tempo control slider is bypassed, but then
that's speaking from my Duo-Art -- your piano may indeed cut out the
regulator pneumatic as well.  Fast rerolling will not affect the roll
tension that much, but greatly increases the odds of tearing a roll
that wandered a lot during play.  I personally like my rerolling very
slow.

I just clean ivories with a damp cloth with a little bit of hand soap.
All you're after is human finger sweat, so nothing stronger is needed.

Mike Knudsen