By Serial Number yours was made in 1971, in 1971 the lever on the texan was changed to a square lever, same as on the octagonal-barrel models and a ramp front sight without hood was put on and the saddle ring eliminated and a new folding semibuckhorn rear sight introduced. (Brophy's book info) if original this had to be a very early 71 to have the saddle ring, the 1970 models were the anniversary models with the medalian embedded in the stock. Don't know what to tell you. If it doesn't have the square lever and other model changes could be one made in 70 but not serial numbered (receiver) till 71, just don't know.