I just picked up a Daisy model 27. I can barely make out Daisy Mfg. Co. Plymouth, Mich. Daisy 1000 shot mod.27 U.S. pat. Aug.17, 1915, others pending, on the rear of the receiver, close to the stock . Is it collectible? It has surface rust on it but it cocks and fires. Any info. is greatly appreciated. Thanks.