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.
-Lionel had round corners in the Bakelite base of their keys. All others were sharp square.
-Lionel had a different angled knurling pattern on their lock nuts. All others had a normal straight vertical knurling pattern on their lock nuts.
-Lionel had the company name "Lionel Corporation" cast in between the trunnion supports. All others didn't have a company name written anywhere.
-Lionel painted their frames black. All others didn't paint them.
-Lionel had the Lionel logo cast in the bottom of the Bakelite base. All others didn't have any marks.
-Lionel installed position pins on all wire posts (rear and inner posts), to stop this posts from turning or getting loose during usage. All others had them only on the rear posts, the ones that are used for training. Lionel located their inner posts position pins in order to form a 45 degree angle.
All this extra features makes Lionel keys easy to spot and to be recognized.
Of all J-38s, Lionel seems to be the more common ones.They are recognized as being the ones with the best quality and attention to detail of all J-38s made.
After 70 years, thousands are still in use today in the hands of fellow Ham Radio CW Operators.
Lionel Corporation no longer produces this keys but the Company is well known and are still in operation. They manufacture Electric Toy Scale Train sets.Their toy products had set the standard in the USA for decades.
Got my Lionel J-38 CW key on eBay but it was incomplete (otherwise I could have not afforded it). Was missing the most important screw: The gap adjusting screw and it's corresponding lock nut.
The special fine threading is no longer common. You can find the Tap and Die (ordering from the USA) to make this threads but the special external knurling on the lock nut, was a different thing.
Jack Burks, K4CNW, a fellow member of the Straight Key Century Club, came to the rescue and, knowing that it was an impossible to find the obsolete screw in my country, looked around, found the parts and sent them to me. My key is again complete with all its parts and all are original from Lionel.