In the movie, "Mogambo," it was noted that the player piano keys were
not moving.  I seem to remember that I saw the roll moving and noted
the keys myself.  However, my Winter & Co., New York, player piano had
an on/off lever that disconnected the key movement when operated.

I imagine the player piano in the Mogambo movie was probably in its
genuine location as shipped out from the UK when new, as many people
from Britain moved out there to "make their fortune" as it were in the
pioneering days.   Most, if not all British player pianos (correct me
if I am wrong) never had the keys moving with the player action at all.

Stephen Bentley
Vancouver, British Columbia