Look at the serial number and subtract the first 2 digits from 100 to get year of manufacture if its serial numbered like the Marlin lever actions. this works up till 1972 or 1973 I believe. I have a 1971 Marlin Texan straight grip and the first 2 digits are the year manufactured. Prior to this type of stampings they used a different nomenclature of indicating the date of manufacture. I might have been back in the 50's when they used a different procedure.