I loved that episode of Twilight Zone, and I asked a friend the same
questions years ago.  This is what he said:

  "It definitely is a Duo-Art reproducer.  When paused I could see the
Themodist pointer that comes out of the top of the tempo indicator
folded over in the horizontal position and the Duo-Art tracker ears.

  "The on/off button is on the opposite side from the ones I have seen
but not too surprising.  In a pull back shot with the title you can see
the fall board the gives the name of the piano with 'Duo-Art Pianola'
underneath that.  It's blurry but there if you know what to look for.
I can't make out the brand of piano, it's a single word, though; Stroud
or Weber maybe.

  "I also noticed the rolls they had sitting on top of the piano after
it was moved.  I saw two Ampico rolls, which would not even have played
on that piano -- the coding on the end would have shifted it into rewind
-- and a couple regular 88-note piano rolls.  It's blurry so I could
have missed any Duo-Art roll present but I know the two Ampico labels
and QRS roll box for sure."

Of course that was on a blurry VHS cassette at the time, maybe someone
with the DVD version can provide even more details.

Hope this helps,
Michael Hamilton