WHAT IS IT ?
I can say that it is not from a 3"/50 Mk 33 Mod 13, or a 16"/50 Turret. My best guess would be that it is a monitor for a mount captain to verify operation of various components of his mount. I guess ‘mount’ based on the single elevation lamp.
Possibly not from a gun mount, but rather the gunfire control system director (such as the Mark 37 or Mark 56) which did the tracking of a target and transmitted the info to the gun mounts (via some intermediate steps).
Any idea what size gun would use this ?