I just bought a Daisy No. 25 pump air gun that has a wooden stock and forearm. On top of the receiver are 5 patent numbers and that it was made in Plymouth Mich. What's neat it came with a cork tube and a model 300 telescope sight. Patent no. 2,155,391. I have never seen the sight before or the cork tube. I'm thinking that these are somewhat rare. Any info is greatly appreciated. Thanks.