plastic grips for luger

The grips you describe are not original to your pistol. The original grips on your pistol did not have the circle you describe. If someone sold the pistol to you as all factory original (aka, "matching"), they defrauded you. Otherwise, you describe a very nice luger. It has been about four years since I was at the American History Museum of the Smithsonian in Wash DC but when last there, the WW2 display included a luger intended to represent a GI souvinier from the war. It was in actuality an East German police pistol with the very grips you describe. It was prominent in the case and I often thought it would be wise to correct the display--seems an institution as fine as the Smithsonian would be more accurate than that.