I recently obtained my first Luger which is identical to the one pitcured (not quite as good condition

) and have a couple of questions. First, I can't tell if it is a model 1908 or 1914 (remember I am a Luger novice). She is a DWM made in 1915 just like the one pictured here. Same markings as far as I can tell. Second, mine doesn't seem to have any unit markings. I assume the markings would be on the trigger guard if there are any. Does this mean anything special?
Thanks!