Introduced in 1954, dropped in 1971, 410 gauge, 125 to 130 in excellent condition, down to 70 in as a good fence post. If your gun was made prior to 1968 it wouldn't have a serial number and there's no way to date it. Even if it had a serial number I don't know of any year list for it. People just don't seem to care when they were made since there's no collectors interest in it, it's a "working gun". You could try bluebookinc.com but they charge a fee. The year manufactured would have no bearing on value. Best I can do.