I have a chance to get a 1918 DWM Luger and don't know enough about them. There is no serial no. on the flat area on the left side, just a small looks to be Imperial proof mark with a large capital N below it. Sorry I don't have pics, also don't recall seeing a sn under the barrel. I know pics are needed but I don't have long to decide on getting it. The sn on the frame, sideplate and toggle all match.