Advice needed: 1917 DWM Refurb?

I am new to Lugers. I have been looking at a 1917 DWM. It was supposed to be "all Matching". The frame # matches the clip and most of the smaller parts. There is a different 4 digit serial # on the Receiver. I think it may be a police or military post war refurb. The chamber is not double dated. I have downloaded the proof marks info from this fine site. They will help when I check the gun again. Could someone suggest anything else that I should be looking for? This piece comes with a very nice holster marked "KernKlause

New ULM

1915"


Only the trigger is strawed. The rest of the parts are blued. Overall blue finish is about 95% and is an even color. Thanks for any help you can provide.