Here we have a very collectible Luger P08 manufactured in 1920 in the DWM ( Deutsche Waffen- und Munitionsfabriken) , which translates to “German Weapons and Munitions Factory”. This was the name of the company that initially produced the Luger pistol, also known as the P08, starting in the early 1900s. This gun has all matching numbers from what I can tell, the magazine has no numbers that I can see. There are extra markings on the front grip strap which will need further investigating. From what I can find so far it could of belonged  to the Berlin police from 1922 I am not 100% sure of my findings hence, I recommend you do further research to confirm what this marking actually means. The marking is S.B. 12065. As you can see in the picture.