Thanks, Peter...for the great follow-up photos.
If the concensus is that your gun has its original finish, then the defacement of the chamber crest is most unfortunate...as Ron Wood said...your gun is a remarkably well-preserved M2.
On many M2 guns, you will see a "bruise" in the wood along the right-side grip panel...just to the left of the magazine release spindle. This is usually caused by the gun being in the AE holster and having contact with the back-side of the metal closure stud on the inside holster body.
The reason for why the M2 crest was removed is still the mystery and I still think it would narrow the collector-interest in your gun...
The sequence of when proofs are applied and whether before or after bluing is quite a volatile area of study.
I do not think DWM applied the same methodology to all the guns they made.
It is very likely the M2's (maybe in the under 1000 SN range) had some of their proofs applied after bluing and other guns in the later contract had their proofs applied before bluing.
On some of the DWM-Swiss guns, you will always see the chief inspector's stamp on the left side of the receiver done before bluing, but you will see other smaller Swiss cross stamps and EB stamps applied after bluing.
On guns with "Germany"...you will see M1900 and M1906 guns with both halo and no-halo around those "Germany" stampings. Which is right and indicates an original finish ? ( I think both may be right...).
I think the variablity in stamps with halos and without halos may have been dependent on whom the inspectors were (either in-house at DMW or coming from a foreign country) or if an outside proof house was used or where the batch of guns in production were on the assembly line and if the inspector could be scheduled in time to do his/her inspection before the next production steps, which may have been the bluing process.
Lots of variables to consider.
BTW...if I owned your gun...I would be in the dilema of trying to decide whether I would have the M2 crest recreated by a talented engraver and have the rust-blue finish blended back in. (Of course, I would tell the next owner of this restoration work when I re-sold it...)
When I see your lovely gun, I cannot help to think..."what an absolute shame...".
p.s. Dwight asked a relevant question of whether you can see bluing deep in the pits (and I would ask in the bottom of some of the dent/dings on the gun). If bluing is present, it would likely indicate some bluing touch-ups have ocurred.
