What is it?

My dad gave me a luger and I don't know anything about it.I was wondering if anybody could help.

1.It has DWM on toggle

2.#28 German nitro on receiver above the locking bolt and another one "sideways" in front of the toggle knobs.

3.Has Gesichert on safety and Geladen on extractor.

4.Has wood checkerd grips and stock lug.Also has Germany stamped on back of gun

5.7.65 mil and serial #85000 range. Does serial# tell what year it was made?And I think it has a 3" barrel


Thanks

Earle