In 1938, Elgin introduced the Lord Elgin series of wrist watches. These were a premium product, with 21 jewel movements, and cased in 14k gold filled or solid gold (and a few in platinum). As I've shown in previous entries, the finish on the movements was also of a higher grade. Elgin continued to sell the 7, 15, and 17 jewel watches as well, taking no effort to distinguish them from each other. It wasn't even always clear from the ads what the jewel count of the movement was.
(The Lord Elgin name had previously been used on some of Elgin's pocket watch movements, but only on the movement, not the dial. In their 12s 'Streamline' series of watches, for example, there were two different Lord Elgin movements, the 450 and the 451. These were 21 and 19 jewel movements, with gold trains and jewel settings.
Prior to that, some of the first watches cased at the Elgin factory seem to have been the 'Lord Elgin' series, which were 14s, and thinner than others. I believe there were even earlier examples as well.
In 1941 (as near as I can figure it), Elgin introduced the 'Elgin DeLuxe' wrist watch line, and I believe they also stopped making 7 jewel watches (apart from those made for the Gov't.). They now had three levels of quality: Elgin, which denoted a 15j watch; Elgin DeLuxe, which denoted 17j; and Lord Elgin, denoting 21j watches. I'm in the midst of either collecting or cleaning the first series of Elgin/Elgin DeLuxe/Lord Elgin groups in the wrist watches, so I have no complete series to show...yet.
But! At the same time Elgin introduced the Elgin/Deluxe/Lord division, they also introduced a new line of 10s pocket watches. These contained newly designed movements, rather than reengineering old ones. These watches were smaller and thinner than 12s watches that had previously dominated the 'dress pocket watch' market. And Elgin made them in the same 3 levels as the wrist watches. Curiously, they did not carry this through to their 16s watches.
The movements were the 15j 546 in the 'Elgin' line, the 17j 542 in the 'Elgin DeLuxe' line, and the 21j 543 in the 'Lord Elgin' line.
Here's a 546 from 1941-42, in rose gold.
A 17j 542 Elgin DeLuxe, also from 1941-42
And here is a 21j Lord Elgin 543, from 1949.
The difference in finish among the 3 movements is more apparent in this picture...
Here you can see that the 546 has a flat, brushed finish, whereas the 542 and 542 have a brighter satin finish. Each grade has its own distinctive finish on the ratchet wheel as well. And of course, the 21j 543 has a cap jewel on the escape wheel and pallet, and a micrometric regulator. Note the cutout in the case to the right of the balance cock for the adjusting nut.
There's another salient fact about this series of movements. They are not so much pocket watch movements in the vein of Elgin's long line of pocket watches. They have more in common with Elgin's wrist watch movements. If they look familiar to any of you who have ever worked on an Elgin 8/0, it's for a reason. Allowing for the different layout (open face for the 10s vs hunter for the 8/0) they're essentially the same, on a larger scale!
This is even more clear at the level of the parts. Not only are all the same parts there in both, they are all almost the same SHAPE! It's like the 10s PWs are just overgrown 8/0 wrist watches!
NOTE! I inadvertantly left out the clutch spring on the 8/0 (the smaller shepherd's crook-looking thing under the pillar plate), but trust me, it's the same thing in miniature.
These watches are a bargain these days, as are most 12s and smaller pocket watches. BUT, they fit the watch pocket in a pair of Levis perfectly, and they keep excellent time. And since they have all the same bits in the same places as an 8/0, they make excellent practice watches, to build your confidence before tackling a wrist watch. On the other hand, if you've been working on wrist watches, these are EASY!