Hi
This fine Luger is a 1910 made P09. If you look close at the last pic. you can se a small proof stamp just above and to the rear of the trigger. This means the pistol was brougt back to DWM in 1913to have the "hold open" added.
Strange about the ser.# It is supposed to be located on the front of the frame just under the barrel, but should end on "49" as you can se on the other parts wich are numbered to the gun by the last two digits in the serial number.
Hope this helps