That SN (5 digits following the "N" rather than 6) would place the date of manufacture in the 1969 to 1972 period, more likely toward the end of that range. I don't have a photo for you, but the gun could have shipped with either magna-style or target stocks. S&W stock design was changing rapidly at that time, but it's likely that your gun did not have stocks (magna or target) with the raised diamond around the screw escutcheon, and target stocks would have had the large football-shaped relief, but not the newer complete cut-away.