Black Widow: Fake, Rework, or What?

I agree that the grips are Russian post WWII replacements (some are also made with verticle groves). I've never seen a true Russian rework that was renumbered, unless it was just etched, most just have mis-matched numbers scratched out. The East German were expertly re-numbered with correct dies. Don't put much stock in the absence of import marks. Many such lugers were bought in Germany by U.S. military personnel via "Rod and Gun Clubs" in the 80's and 90's and brought back....they never had import marks. The out of sequence is a difficult nut to crack as has been pointed and at any rate it is not related Ku assembly (which is also not very well documented as to really where and why it occured).