50-500 usd
50-350 usd
0-525 usd
200-500 USD
A browning light 12 auto-5 shotgun ranges in price from 340-735 dollars depending on overall condition and what type of barrel is on the shotgun(vent-rib,or no vent rib).
I will assign 2 values to your browning light 12 auto-5 shotgun.Both are based on your shotgun having between 60%-90% of its original finish remaining.One value is between 340-450 dollars for the plain barrel model.The other value is 415-630 dollars for the vent rib barrel model.
Your Browning light weight auto-5 shotgun,which was made in the year 1963 will bring between 250-550 dollars,depending on the type of barrel that is with the shotgun,and the overall condition of the shotgun in question.
A Browning auto-5 light weight 20ga shotgun in grade I value will be based on a range of original finish of between 60%-90%.This shotgun with a plain barrel will be between 450-630 dollars.A vent rib barrel model will be 585-850 dollars.
The PZ found in the middle of your serial number indicated that your browning light twenty auto-5 shotgun was made by browning in 1981.
Your Browning Light Weight 20ga auto-5 shotgun which was made in Belguim by FN for Browning in 1964 will have a value of between 460-600 dollars for a shotgun with the plain barrel,and a remaining finish of between 60%-90%.If you have a vent rib barrel 20ga.then the value would be between 575-850 dollars for a shotgun with the same percentage of original finish as quoted above.
$350-$850
The light twelve refers to this shotgun being a light weight model of the Browning auto-5 shotgun.The difference in weight was 10oz.
No way to answer without a detailed description of all markings, finish, barrel length, condition, accessories, box, papers, etc..