Question on inverted serial letter suffix on Luger

[mrerick]

I just looked at the study Tom referred to, and the "3" digits on those magazines and the ones here look the same to me. so do the 6 and 9 digits. i must be missing something. The dies normally used on the frame of the gun were different than those used on the magazine.

I'm now leaning more to factory worker upside down stamping error.