THE MAGS WITH MSCO / USCO WERE MADE IN PHILADELPHIA PLANT. ALL OTHERS WERE MADE IN CHICAGO.

BLACK CIRCLE WAS ADDED BY COMPUTER TO SHOW LOCATION OF FAINT CIRCLE TOOL MARK.

The circle could be where the new outlined block letter U die was to be inserted.   The fourth version is another Blank Magazine. There is no markings at all on the inside or outside of the body. This is a completely new set of tools for production. The tool marks from this magazine are different than any of the previous Bridgeport address box magazines. However, the tool marks are the same as the last of the five versions.

The fifth version has new front face markings. The markings are a justified type font with an outlined letter U on the outside of the magazine body. Are you confused yet?  I am just warming up!

AUTO-ORDNANCE CORP
BRIDGEPORT, CONNECTICUT
REG. IN U.S. PATENT OFF.