10/12/17 - This is an original WW1 Navy Luger magazine with an early style serial number on the base. The serial number "3102" runs horizontally down from spine-to-spine on the magazine base, which is the earlier style of numbering pre-WW1. The base is also stamped with an crown/M Navy proof, and there are concentric circles on either side of the base. The magazine tube has some surface patina and normal wear, but no rust or pitting. The spine of the magazine has a unit number (?) "1690". I've seen this on WW1 Navy Luger magazines before, but still don't know why some have stamps on the spine. The spring is strong and fully functional.