Hi All,  I have a 1924 Marshall & Wendell Ampico A with the wire
external tracking ears (arms).  It tracks beautifully but the roll
is off-center to the right.  The tracker pneumatics have been restored
and the leather pads on the tracker arm valves have been replaced.

What is the _correct_ way to adjust the location of the arms to shift
the location of the roll?  I see that the two vertical tubes, which
are covered by the tracker arm leather pads, are each held in place
by a screw.  It would appear reasonable to loosen the screw and wiggle
the tube (from behind, easier said than done) to raise or lower it and
thus change the position of the tracker arm.  However the screw head is
inaccessible because the tracker arm is in front of it, unless the arm
is first removed by taking out two screws and the arm retaining plate.

It seems awkward to have to remove and replace the tracker arm after
each adjustment.  Is there a better way?

Thanks,
Pat DeWitt
Fort Wayne, Indiana