The character below the serial number seems to be a "r" in lower case. Both on the bottom of the barrel and the front of the receiver. And the barrel has the crown and N on it. The bottom side of the side plate has a 48 on it--I noticed. And a "2" on the inside of the side plate.
I have another question: DWM had a name change in 1922. It changed to BRIW. Does this mean that any Luger that has a DWM on the toggle--was made in 1922 or earlier? Or the toggle was made in 1922 or earlier?