Barrel markings observation
 

I was comparing my Parker Reproduction 28 with my friends yesterday and we noticed on my barrels it is stamped 70 mm after 2 3/4” and on my friends it is missing. My serial # is in the 800’s and my friends is in the 1100’s. My gun has the F stamped under the barrels where my friends is stamped 00 for the frame size.

Matt, your gun's serial number is in the same range as a friend of mine's gun that is shown and discussed in this thread: http://parkerguns.org/forums/showthread.php?t=17399
His and yours both have the 70mm stampings and are sans the frame size stampings. Would your gun happen to be fitted with an 0-frame stock?

My stock measures 4 5/8” roughly so I would call it a 00 stock.