I was a USAF Combat Arms Training and Maintenance specialist/technician during my time in the service, and based on my experience inspecting and shooting hundreds of these weapons, it looks to be a genuine USAF M15 to me. The only other things I can think of to check, is the model number "dash number" (if there is one, it will read "15-1", "15-2", etc.), stamped inside of the frame cutout where the cylinder crane is located when closed, and the serial number, to make sure both these numbers match the era in which the revolver was produced (according to the packaging).
Originally Posted by plentyofpaws
If it is original, and in the condition shown, it may well be worth quite a bit more than the average S&W model 15 to a collector of military arms. Be aware, however, that it could be a Vietnam-era bring-back "duffle-bag special", and as such, the weapon/serial number may have been reported as stolen at some point in the distant past, depending on the conditions of its release from service. There was at least one legal way for an officer to obtain a personal weapon that he had used in a time of war (awarded to him at his request, during retirement), but that would seem to be inconsistent with the condition of this weapon (doesn't look like it was ever carried), and usually, there needed to be a personal connection to the weapon (used it save his life, etc.).
Interesting photos, in any case. I have a non-military model 15 that I purchased after my retirement, simply because I had spent so much time training folks in their use, and shooting them myself. It has a worn finish, but shoots well, and I enjoy taking it out and shooting it (on rare occasions) quite a bit.
Thanks for the trip down memory lane...
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)