Can you help me figure out how old this BT-99 is? It is a 32" barrel with choke tubes and adjustable stock. The number under the top lever is 01632PT199. There is a number under the forearm stamped on the bottom of the barrel. It is 001632. Any help appreciated. Have an interested buyer and he wants to know when the gun was made. I have no idea. I bought the gun used in the 90's.