While you do not state weather your Browning superposed lightning is a 12 gauge,or 20 gauge.I am going to assume that it is a 12 gauge.The serial number indicates that your shotgun was made in the year 1959.If your 12 gauge Browning shotgun has between 60%-90% of it,s original finish remaining and a good set of bores it will bring between 750-1,050 dollars.The same value applies if this shotgun is a trap model also.