I have an Estey player piano with serial number 56942.  I am trying
to determine if it has a Standard stack.  It looks like a Standard
two-valve unit, however the tracking pneumatic is mounted on top of
the spool box.  Also it has a split stack with cutouts operated by
buttons on the key slip for soft playing for either the bass or treble.
Does anyone know if Estey ever made their own stacks?

Herb Ziegler