I have 2 guns im looking for info. I just got an m1 carbine i know its after wwII. Its a plainfield machine co. Does it hold some value. the only serial #`s on it are F325. the other gun i have my grandfather gave me many years ago is a 12ga. over and under made in czechoslovakia it has stamped under it 581-04 mod4 uh.brod 26220. This is the gun i really want to know about my grandfather dont remember much, all i know is he bought it for me when i was younger .