Side plate numbers???
 

Ok, was stripping the blue off of my tird 1920 commercial (plumb brown) when I noticed that the first two digits of the serial number were on the inside of the plate. Now I know that I have seem them on the reverse of WWII guns, but not on early post Imperial. The number appears on the opposite side of the last two digits in the commercial location. I can take a pic if anyone can't follow my gibberish. By the way I looked inside of my 1908 and 1923 commercials as well as several of the 1906's and none had the first two digits inside.