Yes they did, but only on special order request through the Gun Dealer. This work was done in St Louis at the Browning shop, but it is difficult to determine if it was done by Browning. There is no such thing as "Factory Installed poly chokes". Even if Browning St Louis installed it after the gun was made, it is still unoriginal to the gun
No.
They started up again this year.
Not enough profit.
Check Browning's web site. They have sn data.
Your prefix of zero G was assigned by Browning to auto-5 lightweight shotguns that were made in the year 1960.
The 2Z prefix to your shotguns serial number indicates that your Browning auto-5 was made by FN of Belguim for Browning in 1962.
No. During WWII, Browning had Remington make an American A5 for them. Those guns were stamped Browning Arms Co St. Louis Mo., but they were actually made by Remington in New York.
No way of knowing without you providing a much more detailed description of your shotguns overall condition.
How do you remove the breech block on a Browning A5 16ga shot gun
No
It depends on percentage of original finish still on the gun. As long as there are no recoil pads, or polychokes, then $400-$1200 based on condition. Check gunbroker.com for comparing. auto5man
The 6G prefix dates your shotguns manufacture date to the Year 1966.