The easy answer is , Nitro Hunter was a trade name used on firearms the H&D Folsom used on firearms furnished to Belknap Hardware. Folsom had their own in house gun company, Crescent firearms Co. Which manufactured firearms for Folsom's distribution. H&D Folsom was in business from the late 1800s untill the 1930's. However I have never seen any information that Crescent ever made a automatic 22 rifle in their shops ( but then again there are a lot of things I haven't seen ). Now, here's an interresting thought, Crescent Firearms Company was purchased by Stevens around 1930. For about 10 years Crescent stayed in business and then faded out at the start of WWII, during those 10 years they still furnished Trade name firearms to their previous customers and if they didn't have exactly what their customers wanted , then Stevens did, in fact , at the end of Crescent's business life , all of their guns were made on Stevens machinery. I believe you have a a model of Steven's/Savage rifle. Could be wrong and way off the mark, but then again maybe I'm right? Other input??