It is a 151 semaphore with the somewhat "rare" red arm perhaps made 1947-48.
It will operate on any NO circuit (on/off). The middle post is common, one outer post is for the solenoid, the other post is for the lamp (14V #53).
As you note, the base, pole and several other parts are common to both the 153 and 151. Some 151 production retained 153 on the base. It was later modified by Lionel.