The green Anderson & Co. "1920's QRS recording player piano" recently
sold on eBay is certainly not the instrument used by Cook in his studio
at the Aeolian Corporation building, 33 West 57th Street, New York
City.  For another view of that piano, go here:

  http://www.doctorjazz.co.uk/cookbw.jpg
 

Clearly visible here is the name Melville Clark, cast into the plate
at the upper right.  Just below is "Chicago", mostly obscured by a
metal shaft.

Both the Anderson and Clark pianos have identical sloping keyboards
added later.  The Clark piano is obviously a former player; the Anderson
is not.  Both instruments likely came from the Cook residence in Mount
Vernon, New York.  (I was never there, so don't know for sure.)  Anyway,
I can't help but wonder if the Clark upright ended up at the QRS plant
in Buffalo following Cook's passing, where it may even remain to this
day.  Anybody know its present whereabouts?

Incidentally, note the pressure bar on the Melville Clark piano.
It was shaped this way to accommodate five copper-wound unisons in the
lower tenor section. Overall, a tonally remarkable scale.

Jeffrey R. Wood