It was quite obviously made by a leather-working hobbyist, probably for his own use and of his own design. The lacing is somewhat crude and was probably an afterthought.
Now that I can see better images, I agree it appears home made. Crude? Not compared to what I can do to leather! That is why I have leathersmiths on file.
Yes. A "hammer guard" is usually on the side of the holster toward the carrier. It is ti keep the carrier from being chafed by the hammer and his shirt damaged or exposed to snagging the gun. On the front of the holster as that one is serves no real purpose
I had always seen the guard on the backside. When wearing it the gun handle sits like it would on a Jordan style holster. For quick access more than concealment.