Krieghoff Luger?

[surf2k2]

New member, first post, hope you enjoy:

An old friend of my father brought this luger by the house. He believed it was Kreighoff and asked me if I could tell. As you can tell from the pics, there are only proof marks on this gun and I have never seen engraving like this on a gun.
History - the gun had gold leaf on the engraving, but the previous owner had it removed.

Question 1- is this a Kreighoff luger?

Question 2 - can you tell anything from the engraving?

Question 3 - can you put a value on a gun like this?

I know it is difficult to judge a gun from pictures. Any information would be appreciated.

Thanks