Looks like it might be Model Power. The square base looks similar, but the color of the Stop sign is not correct. The MP one is white on black, not black on white.
Weren't The NJ International painted silver? Of course this could be repainted. Somehow I am believing this is another maker.
Thank's guys for identifying this signal! Much appreciated and will see if I can get one... Regard's, Brock Joubarne
For anybody that is looking for crossing signals, non-operational, check out "Osborn Model Kits" They are laser cut wood that must be assembled and painted and you can get crossing guards as an accessary if you wish. They may not be the most prototypical but they are inexpensive enough that you can scatter them across even a large layout without breaking the bank.