"Field side holster" is the selle's term for this Heiser-Keyston, which H-K itself called a "safety strap belt holster". It's not that his title is incorrect; it's just that it's not a generic term.
I think it's worth wondering what a threepersons is, and is not. My description is perhaps what it has come to be, rather than what it was, because Myres himself defined a threepersons in three different styles: as a belt holster, strong side, with the trigger guard hoop fully exposed, with it enclosed, and as a shoulder holster!
This one from Heiser is, I believe, from their 1922 catalogue, though it has two 1908 dates on front and back covers.
This one is what we believe to be Myres' first holster catalogue, 1931.
Ditto; note that it is a "skeleton" spring shoulder holster.
Myres 1938, when the classic Myres scabbard appears, of FBI fame.
What we believe to be Heiser's 1938 or 1939 catalogue.
The original Threepersons holster I was referring to is this one, which I cadged from a thread on this Forum, and is dated (it says) from the late 1930s. The holster that Lobo shows is a factory Myers that was not introduced until their 1938 catalogue.
http://smith-wessonforum.com/s-w-hand-ejectors-1896-1961/100128-s-ws-tom-three-persons-holster.html See post #34 and another that follows.
In my definition I omitted that the classic threepersons also has a closed muzzle. And that it appears that the ride height was defined by the grip being high enough that the shooter's knuckle could grasp the pistol with full clearance at the top of the belt.
You'll see from both the Myres, and the Heiser catalogues; and the black Threepersons from the mentioned thread; that a thick welted seam appears to be essential; note that the much older Heiser pocket holster is riveted there and likely did not have the welt.
So: I call them all "scabbards" and I leave old Tom out of it altogether. Scabbard is truly more dispositive of the concept.
