Hi again Aaron,
After studying your photographs a while I have decided that my vote must fall on the side of a Luger that has been refinished... This is for several reasons, but let me point out the most obvious to me...
In the photo below, the serial number digit "9" on the takedown lever (B) is similar, but is definitely wider than the "9" that appears on the sideplate (C), the upper receiver (A) and the sear (D). These appear to have been original strikes... but the number on the takedown lever is not from the same tool. Second, the surface of the flat on the takedown lever just isn't (flat) as is normally seen on original parts. It appears to have been buffed which has caused a slight rounding of the surface that used to be flat. The condition of the overall blue appears that it has never been in contact with a holster...especially on the sideplate... IMHO This is not likely on gun of this vintage and when you combine this with the serial number disparity I have pointed out, it adds up to an overhaul. Since the small numbers "42" appear on the the upper receiver and the sideplate, I believe that this gun was repaired or rebuilt at Oberndorf at some point, having some parts replaced, and then refinished and re-issued... and then possibly reworked by someone else like the Russians or East Germans.
lastly, the digit "1" on the takedown lever does not seem to match the other areas identified.
Naturally, this is all speculation on my part, but I believe it is speculation based on sufficient evidence to warrant my conclusions.
just my