A question about my Luger............

My grandfather recently gave me a Luger he purchased many years ago. The markings it has are as follows: DWM 1918

It has two clips with matching numbers as the gun itself. The numbers are 3449. The small numbers all over the gun are 49. There is a number on the handle, LKO146. If anyone could tell me when the gun was made or an approximate value, I would appreciate it greatly. I'm planning on keeping the gun and I want it insured. It's silver colored finished with a pearl colored grip. Thank you very much.