Need Help Dating Stevens 620 Shotgun

[Stoneslinger]

I picked up a Stevens 620 12 gauge today, however I'm having a rough time dating it. There seems to be little information available online, and was hoping someone here might know something useful.

On the right side of the barrel, it is stamped
"J Stevens Arms Co.
Chicopee Falls.Mass.U.S.A"

On the left side of the barrel, it is stamped
"Stevens Browning 620
12 Guage Proof Tested" (yes, it's spelled "Guage")

Where the operator handle slides though the grooves on the barrel, it is stamped
"A.P.T.
11306
W"

On the barrel there is also a number "7" which is circled., and directly below it's stamped "Full".
Inside opposite from the chamber opening, upside-down, is an "S" with a "4". "11306" appears to be the serial number, as it's also stamped on several other places as well.

Anyone have any idea what the "A.P.T." and "W" stand for?

 

[mac1911]

I have several "Stevens" shotguns. The 620 is a Browning design. I'm going to throw this out their but I think mid 1950s was the last of production.
The j Steven arms co logo was dropped in the 1940s I believe as savage took over. So its safe to say its probably pre 1950?
There's not a heck of a lot about these working mans guns. They don't hold a lot of value for the most part.
I have 6 assorted Stevens arms co firearms and all are well used and keep going. There's got to be a "Stevens" forum?