I have Browning 16 gauge shotgun,serial no 57447 FN
On left side of barrel is stamped "ACIER SPECIAL OK
g888 Fabrique Nationale D'armes de guerre Herstal
Belgique". On right side of barrel Made in Belgium
On Butt of stock FN Browning Automatic. Numbers on ejector slide 447 P.V. Has a adjustable choke.
There is no etchings in barrel or receiver, the trigger is not gold and sweet 16 is not enscribed anywhere on gun.
What would be the date and value of this gun,