One thing I haven’t seen mentioned in the paint versus blueing debate is that in the “pre-greeblie” pictures, the entire magazine plate has bluing worn off it. In the post-greeblie photos, it’s only partial. To me it looks like chipping and not an even wear like you would get through usage in that area. It’s too abrupt for a color change. Also, the disc has a clear internal lip. If there was residual glue build up, there would be an an external dimension, not a clear drop off, but from all photographs, it’s smooth up until that lip, right?
Also, the mount has not yet been painted. The cross bar is clean metal and reflective. In addition, the ground scope mounts on the other side are still bright metal also. The production gun on the other hand has a two toned mag plate. The cross bar is now painted and chipping, and the flats on the mount are also painted. So I think at some point, this thing had to have seen paint.
As for the grills, they could have been added post paint also.
One other thing to look at is the brass windage knob. It also appears to have gone from a nice patina to a more black and then worn look.
Well, at least that‘s what I think I see when I look at all the photos. Everyone‘s mileage may vary.
Edit, fixed typos.