Well: At least the frame is 1909-1913 military, as can be seen by the added hold open and replaced front sight, which was done in 1913, but the top makes it a bit confusing. 1909 is the only year not having the year stamped on top of the chamber, but then the proof marks should be on the left side of the chamber. Also most of the numbered parts should have the numbers "hidden" for that year.
In 1910 the proof marks are moved to the right side, and the year stamped on top of the chamber.
I am not sure about the serial numbers for 1910-1913 but as far as I know yours could fit in the 1909 ser# range.
If you look at my album you can see how the markings are suposed to be on 1909 P08
http://forum.lugerforum.com/album.php?albumid=60