I do player rebuilding.  I have found the Autopiano to be very bulky:
big secondary valves, valve chests, pneumatics.  The Autopiano is
always a double-valve stack.  The Autopiano is inefficient when it
comes to the way it uses the lower air pressure.  A Gulbransen action
(love it or hate it!) is an example of a compact and efficient player
action.

In spite of all limitations, when well rebuilt the Autopiano is "easy
to pump".  The Autopiano has very big and powerful bellows to overcome
the above-mentioned design drawbacks.  Autopiano's parent company also
owned Standard; both player actions were made very similarly.  The
rebuilding is very straightforward.

Autopiano is a more bulky player mechanism than most.  There are more
places to check for leaks than most 88-note players and the rebuilder
has to be thorough.  Some leaks are hard to find.  Use of several
different leak testing methods is best.

Thoroughly seal all wood.  Use a good quality, fine nap leather on the
valves (primary, secondary and flap).  Use good quality bellows and
pneumatic cloth, replace gaskets, tighten screws.  Make sure there
is not excessive valve travel.  Make sure valve button adjustment is
correct.

Just to make sure, I seal all gasketed joints with shellac so the
player does not become difficult to pump in the winter.  I find that
when I glue a piece of kid skin to the flap valve leather it makes
a noticeable difference in ease of pumping.

Bill Maguire