My own two cents on the discussion of the "less than stellar" newer
players.  My own experience of the newer players built after the Second
World War -- such as the plastic-valve Aeolian-American units, the
instruments built by Universal, and others -- is that, from a design
perspective, they're good units.  The problems (and there are many) is
not in design, but in production.  Shoddy workmanship and poor choices
of materials seem to have been the norm, rather than the exception.
The pianos themselves are often only passably adequate, I suspect in
part because of a perception that a higher quality instrument would
increase the cost prohibitively.

In the first 30 years of the twentieth century, everyone in the piano
business was making and selling player pianos, and if your firm was
selling players that didn't work at least as well as your competitors,
you would be facing economic peril.  The situation was different,
though, towards the end of the century, when a customer wanting a new
player had only limited choices.  A player that could function passably
on the showroom floor, if only long enough to sell, was really all that
was needed.

The Aeolian-American player action responds wonderfully if rebuilt
with new, properly built valves and everything is re-covered with
quality materials.  Ditto for the Universal players.  I think the
problem with these instruments is more one of shoddy construction based
on economic considerations, rather than one of poor initial design.

Bryan Cather
St. Louis, Missouri