Engraved artillery luger

[Van]

I am hoping someone may be able to help me trace the history of my artillery luger. The weapon is engraved and has been reblued. All the parts are not matching. The grips are hard rubber and have a brass overlay, which includes the Nazi eagle and swashtika. The grips appear to have been made to fit the pistol. The clip with the weapon is a Mauser with 1940â??s markings. The plastic end piece is engraved with a fleur-de-lis.
On the left side of the frame are the DWM proof marks and the Army acceptance proof. It is dated, 1917. On the frame are two proofs; crossed pendants with the letter and numbers D, 5, 0 in the quadrants and the second is a crown on top of a circle with the letters BP in the circle. The crossed pendants proof indicates the weapon was a capture weapon or was imported into England. I do not know what the letter â??Dâ?� or the numbers â??5â?� and â??0â?� signify. The second proof is that of the Birmingham Proof House and the circle around the proof was used to indicate a weapon is not English made. I purchased the weapon from a dealer in North Carolina. He indicated he could not supply any past history of the weapon.
My question is, has anyone ever seen a weapon like this one before? I am assuming the weapon was either â??madeâ?� for sale from parts in England then proofed before sale or was a presentation weapon put together during WWII by some level of the German military and was a capture weapon taken to England.