Go to Browning.com and you can download a manual
It shouldn't say light twelve on the barrel, but on the receiver. Light twelve means that the gun is a light weight version of the standard Auto5 shotgun.
The serial number L52789 indicates that you have a Browning light weight model,auto-5 shotgun which was made in the year 1955.
YOu must provide the serial number.
1962.A Browning light 12 shotgun with the prefix of 3G indicates that your shotgun was made in the year 1963.
Good shotgun
Readily available from Browning.
This is a Browning Auto-5 Lightweight 12 gauge shotgun.
The 4G prefix to your serial number indicates that your Browning auto-5 light weight shotgun was made in Belgium for Browning in the year 1964.
The 0G prefix indicates that you have a Browning Light weight auto-5 shotgun,chambered in 12 gauge.This Browning shotgun was produced by FN of Belguim for Browning in the year 1960.
The light twelve refers to this shotgun being a light weight model of the Browning auto-5 shotgun.The difference in weight was 10oz.
Your serial number indicates that your Browning light twelve auto-5 shotgun was made in the year 1955.
This is a mixed question. Which gun do you have? An Auto-5 Light twelve, is not a pump shotgun, it is a semi-automatic. Since 1979 is before the Browning Pump Model BPS was introduced, It is assumed you do have an A5. Value depends on condition. Typically with average use, these guns sell in the range of $500-$750 depending on condition. Mint in the box will go $1000+, but remember that this model has a fixed choke in 1979 and won't bring as much as the later Janaese made Auto-5's. The nickel plating you mention is not Browning factory finished. Browning never plated an auto5. You could have a silver receiver that was custom engraved, but it wouldn't be plated. If someone actually did nickel plate the gun, it could decrease value.