New Britain / None Better / Handle Lock did indeed make 1/2" hex drive socket sets like that, but they most likely would have been marked with a completely different patent date - December 12, 1922 - which was when patent 1438900 was issued to one H.H. Chase. (That particular patent actually applied to the design of the stamped-steel socket
holder, which your set does not have, but was used on a variety of different items from 1922 at least up into the 1950s.)
These are the only two listings I have which show a New Britain made 1/2" hex drive set like yours:
What you actually have there (at least the "ell" handle*) was made by the R.F. Sedgley Company. The patent date of December 31, 1918 applies to patent 1289558 for their "Hexall" hex-drive socket sets.
The Sedgley thread is HERE:
https://www.garagejournal.com/forum/showthread.php?t=378656
* The reason I said "at least the "ell" handle" is because I frequently see listings on Ebay for hex-drive sets which have been cobbled together out of mis-matched pieces. More than once I've seen a Sedgley "ell" handle in what is clearly a New Britain made socket set - when the socket holder is stamped "PAT. Dec. 12 1922" and the "ell" handle is stamped "PAT. Dec. 31, 1918" it's not too difficult to figure out.
The conundrum, in those cases, is determining who actually manufactured the sockets, because both look very similar, and there were other manufacturers (Indestro, for one) who made sockets which look almost identical.
If you're willing to go down the "hex drive rabbit hole":
here's a thread that started out about hex drive ratchets:
https://www.garagejournal.com/forum/showthread.php?t=379751
here's a very short thread about 1/2" hex drive sockets:
https://www.garagejournal.com/forum/showthread.php?t=377884
and here's one that discusses some other makes of hex drive sockets:
https://www.garagejournal.com/forum/showthread.php?t=378370
... and welcome to the site, by the way.
