It is on the weapon.
If it is marked Light 12, that is an incomplete serial number.
No serial number given.
1965
This is a Light 12 model made in 1970
Your serial number with the prefix of 4G indicates that your Browning light weight 12 gauge shotgun was made in the year 1964.
A shotgun in 12 gauge.
50-500 usd
Basically impossible to value with just the serial number.
1962
It was made in 1953
This gun was made in 1955
By the serial number and guage