This came off ebay. It spoke to me, I don't really collect or have much Armstrong stuff, but I do like me some NOS/lightly used time capsule tools.
This rat looks unused, just getting the plug out and putting back in put noticeable wear on the chrome. Very tight. 24 teeth, works super smooth/low backdrag like pear head Proto rats.
The plug itself is interesting, it has writing on 3 sides that do not have the detent balls.
"ARMALOY"
"ARMSTRONG MADE IN USA"
"F-150" (guessing not the pickup truck
)
Also interesting, the 50 of the part number is stamped onto a little milled flat next to the forged-in FA, I'm guessing there are a few variants. All in all, a cool rat for the collection.