Brauer Bros. was started in, I think, 1898. This is from memory, so I could be a bit off. They are still in business today I believe. Not the oldest holster maker in the US, but darn near it and certainly the biggest in volume of the old makers. They were huge in LE and sporting commercial markets from before WWII until now.
The type of holster you have is called "Hunter Style." I think it came out in the late 20's and grew in popularity with hunters and others for field use into the 50s. As a design style, it represented sort of a "3rd generation" of holster development from cowboy rigs - having built upon the Taft models and Threeperson designs that grew up after the first decades of the century, which struggled to come up with functional designs that worked with double action revolvers and autos. In the late 50s or 60s, S&W started producing that style in large numbers and selling it under their brand. I am no expert in older leather, but have studies some styles and purchased a few items from WWI, the 20s, and WWII.
Based on the weight and finish of the leather in that model, the types of rivets used, etc., I'd guess that would date from before WWII. Thinner leather like that was more characteristic of the mass-produced items of Taft, Brauer, etc. of the pre-war period than the heavier, less well-finished pieces and construction post-war. It appears to be made for a 5" barreled S&W K frame (could be 6", I can't quite tell), which was one of the most popular guns sold during that time, so that fits the profile. 4" is the most common now, but that didn't really take over until the late 60s. It was likely designed to be a bit loose so it could take both a S&W and a Colt. For $4, it's a great touchstone to American firearm history, and it great shape. I do not know what/when the "Moose Brand" appellation means. maybe someone else does. It may help nail down a production period for Brauer.
Again, these are comments of my observations and purchases to accompany some of my older handguns; I'm not a dealer or expert. Others can correct them if they know better!
