311E 16 gauge

Just purchased a 311E 16 gauge, curious as to the year of manufacture and chokes. I also have a 311E 20, and a Fox-B 12 that I love. The previous owner had painted--painted!!!--the stock red, so I've got a refinishing project on my hands. The serial number is A516604. Right barrel marked 5x, left marked 7x.

Any help would be greatly appreciated. I love all the knowledge on this forum. Thanks everyone!

From the little I learned researching my Fox-B & my 365.....a 311 with a serial # puts its DOM between 1968 & 1989 when they ended production. The A-prefix would suggest early in that bracket, but I don't know what the last prefix of that series was.

Jeff

Thanks Jeff! Much appreciated.