Help identifying old miter box

Anyone know anything about this type of miter box:
Note: not my picture

A friend found one of these a while back and gave it to me. I'd forgot I had it until recently, gave it a try today and it works great. Anyone know the manufacturer or age anything really, about it. I don't find any markings on it other than the engraved numbers on the dial on top for setting the angle. Only problem I had with it was I don't have a backsaw tall enough to complete the cut I was trying to make so I had to use a relatively new handsaw(hardened tooth Stanley) the friend was throwing out because it was missing a bolt. It took quite a bit of cleanup because it sat out in the scrap pile for a while before being saved.