With such a fancy logo, I’ve always wondered if there are visual clues as to the ordering of the symbols. In this case the letters S, C, O, and ampersand. There are 9 reasonable combinations (I’m omitting anything that begins or ends with the ampersand). Trying each on a quick Google search, I did come up with one interesting possibility: OC&S, the Ontario, Carbondale, and Scranton railroad. See:
RAILROAD.NET • View topic - OC&S RR - Jermyn, PA?
The railroad was formed in 1888 but this lock looks much newer than that.
Another possibility is the Ordnance Center & School (check Google).
Jim