Signal Electric Mfg Telegraph Key Sounder Railroad Morse Code
Made in the USA, in the 40's, by Lionel Corporation and used during the WWII years.
The J-38 type of CW/Morse keys were used by all branches of the US military. Were manufactured as part of the the war effort by a few specialized US companies. They manufactured them almost identical and sometimes it is hard to recognize the factory that produced that particular model.
Some of the companies were:
American Radio Hardware (ARH), Lionel Corporation, Telegraph Apparatus Corporation (TAC) and there were two more of unknown manufacture: One made entirely of brass including its frame and, the last one, made entirely of white metal including the frame.
They look all the same and parts are interchangeable between different manufacturers.
Very small differences that could give away the possible manufacturer are known.
The most easily type of J-38 CW keys to identify is the one made by the Lionel Corporation.