Below is a series of photos of the player system in a Colby upright player piano. As of now, the system's manufacturer has not been identified. It is entirely possible that Colby made their own player system. Of particular interest is the four-chamber air motor and the (apparent) mechanical/manual tracking system. Also of interest is the exhauster assembly and the devices that are connected between the stack and the exhauster assembly. If my guess is correct, the two similar looking devices on the right and left are vacuum regulators. These are most likely activated by the what appears to be Bass and Treble push buttons in front of the keys. If that's the case, the system most likely has a 'split 3-tier stack' and some degree of expression control. Also of note are the rather huge exhauster and reservoir bellows, which are bigger than any I have ever seen in a player piano.
If you can identify the maker of this mechanism, please write to me, John Tuttle, at: John A Tuttle.
407 19th Ave, Brick, NJ, 08724
Phone Number 732-840-8787