You will need to supply the serial numbers to your shotguns to get the age of your browning shotguns correctly.
You will have to call Browning.
Try Browning.com
Browning.com has sn data under customer service.
Browning never used the letter B prefix for any of there shotguns serial numbers.
The Browning light twelve shotguns serial numbers do not go that high.Please check and see if there are any letters in your serial number,or before or after your serial number.
Browning's web site has a sn search function.
Check Browning's web site. They have sn data.
The 7G prefix to your serial number was assigned to the browning lightweight auto-5 shotguns that were made in 1967.
NO
You will have to call Browning with the serial number to find out.
I show no browning 16ga shotguns made with the prefix okg.to the serial number.Please check your serial number again and resubmit your question.