Thank you again for the great feed back and direction. Mike, the ser number: 4057XX is in the 405K range? The gun came all stock and was purchased by the husband in 1989 I believe ( on the form). He also purchased a 9mm upper and had a local gunsmith assemble the gun. It was fired twice according to the wife...and never with the 223 upper. I asked a local gun smith to look the 223 (original) upper over. He reported back that the upper had little to no use. I asked that he look the lower over and received the same report... very little to any use. She would like to market the gun so I will get on doing that and post some pictures on AR-15 as well. Thank you again... this has been my first experience with a site such as this and I must say you guys are GREAT! Dale