Did you ever figure out what this was? I found what seems to be the same thing
From the looks of yours, ...... I would guess it was a "servant call".
Like in the old movies when the "boss" lady or man would "jerk" or "pull" on a dangling cord in the room ..... and a servant would come running.
Pulling on 1 of the 5 rods would cause the corresponding "button" to pop-up and "ring" the bell ...... which yours has the "ringer" but not the bell.