Interesting Erfurt 1918/1920 with Weimar unit marking

[DonVoigt]

Originally Posted by John Sabato

The surface of this pistol, especially the marks around the circumference of the barrel, appears that someone used some rough sandpaper to remove some surface corrosion or rust ... probably resulting from poor storage conditions.

John,
I agree that could be the case, but I don't think so.
The lines are perfectly concentric, parallel to each other and at right angles to the bore.

The eagle and the numbers seem stamped after the lines were created, at least to my eye.

No signs of any pitting.

I think it just hurried production and no polish.

I've posted two close ups.

Any ideas on the time frame of the eagles?