Not exactly, DWM from 1912 started with 1"ns" , just as did Erfurt when the year changed; with military production. The years from 1908 to 1911 show some strange overlaps.
So there are some years, that did not use all the suffix letters.
DWM commercial production after the change to year dates in 1920 and 21 started over, when the year was dropped, DWM commercials ran the alphabet.
Mauser ran the alphabet to the end; before starting over.
A four digit "e" suffix likely did not appear to 1915 production.
So the OP pistol would likely date to 1915 to 1918.
At least that is what I get from studying Still"s Imperial luger book. See the chart on p15, it is much clearer than my writing.
How is that for mud!
And please, there are no "squirrel" marks on lugers; I have no idea what you mean by that.