Can someone help me identify this player action?  The tracker bar 
has five vertical slotted holes at each end.  I am including a picture
of the only expression box on this Steger grand, serial number 17829.
I guessed some sort of Recordo?

John Dewey
jdent@hughes.net

 [ Steger 17829 expression
 [ http://www.mmdigest.com/Attachments/19/09/25/190925_222046_20190917_155142%20(2).jpg