I have seen just about as many Coinola Cupids with box pumps as with
the vertical pump.  The box pump they used was a smaller pump than
used in the larger pianos.  Over the years Coinola used several
different methods of constructing the crankshaft to the pumping
bellows, and several methods of a spring assist to close the bellows.
My favorite pump has connecting rods and not the canvas connection.

Don Teach - Shreveport Music Co.
Shreveport, Louisiana