The Sport Master was sold around 1991 as a hunting rifle. All I have seen had special stocks with raised combs for use with scopes. Many had laminated stocks. This is the first I've seen with a standard stock. They were otherwise pretty much standard M1A type rifles. I've worked on a few of them in the past. Lee Emerson has one pictured in his book M14 HISTORY AND DEVELOPMENT - THIRD ADDITION VOLUME 2. It's entirely possible that those now employed by SAI have not been there long enough to remember these rifles. About the same period SAI produced several special variants of the M1A of which the Sport Master was one.