Here is an easy way to stop the shaking that I call "the hula" as in
"Hula Hoop."  I used a pool cue with a extra amount of chalk applied to
the tip.  I simply clamped it to a low table at the correct angle to
kiss the edge of the pump flywheel without hitting the side wall of the
piano.

With the motor power off, I slid the table to a point 1/8-inch from the
tip of the pool cue and the flywheel edge.  I then rotated the flywheel
by hand to make sure that the flywheel did make contact, while observing
that it was not out of round.  When I turned on the motor, the hula
effect soon began and bingo, the chalk mark was there in plain sight.

To offset the balance problem, I simply wrapped plumber's solder around
the spoke opposite the chalk mark.

I hope this is helpful.

Bob Maniaci (I love MMD!)

 [ I am imaging your Ampico grand wearing a short skirt of tassels,
 [ like a 1920 flapper girl's dress!  Now play "Shakin' The Blues Away".
 [ ;-)  -- Robbie