They were factory offered and I well remember holding one in my hands at the local gun shop but being a young newly married officer, could not afford one. I was finally able to buy one with the fixed stock and factory extended mag. I tried to locate an original Choate folding stock but was unable and went with a Sile collapsible stock and have loved it ever since. It sits beside my front door and has for years. Could you post some pictures of your original, please?