Well, your pictures are of very poor quality.
I don't know any rebluing process causing this type of marks.
At the safety lever location, white "S" and red "F" look very original, when reblued, these letters are black.
As I can see, these are machine marks produce may be a Monday morning after a Sunday "Beer Fest" or a Friday afternoon and quality control dept. don't see that or let it go as it.
Normally, we will never seen these kind of imperfections on a commercial SIG, BUT, for a military SIG, may be it's a rush on production, and SIG ask for a minimum of inspection on pistol exterior finish., as soon pistol is tight without any "cling & clang" and shot well.
All scharps edges are very scharps, so, we can't see any trace of buffing there.
Crest and lettering on the slide seem very scharps and clear, no fading there, but pics. are very poor.
Money collectors always check for money with defects, may be it's a good idea to keep in a collection a pistol with this kind of defects from SIG, a Company with a SUPER REPUTATION.
How come quality control dept. let go this pistol with these machine marks?
For me, this is a mistery.




























