Question about sideplate numbering convention

[DonVoigt]

Originally Posted by Edward Tinker

Seems like a heck of a pain to mark them in the first place?

Even on 1917 and 1918 Geo?

Not if one was finishing more than 100 side plates in a batch.

Without the inside two digits, one could not tell which pistol it was fitted to.

The very same reason Mauser marked their side plates inside; only mauser marked them on the flat side, not the bottom ledge where the lever pin locks in.

For those who didn't follow the link, here is the picture mentioned above with the inside DWM numbers circled: