You should be able to find a list of gun shops in your area that may have a Browning shotgun of this make.If you do not,I would go to gun broker.com.I believe that they will list a few of this model from time to time.
Gun show, gun shop, pawn shop
1962.A Browning light 12 shotgun with the prefix of 3G indicates that your shotgun was made in the year 1963.
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.
It is the lightweight version of the Browning Auto-5 semi-automatic shotgun.
A shotgun in 12 gauge.