Sam,
The quote below the photo is from the owner. The holster was discussed in a thread about the Charles Greenblatt Company on the Smith & Wesson Forum. The gentleman who posted it is a forum moderator and it was one of the holsters he displayed on his table at the Kansas City SWCA Annual Meeting. These guys know vintage S&W holsters like we know Randall sheaths. Apparently, the numbers on the back of holster correspond with Heiser model numbers, which corresponds with Heiser catalog photos.