OK so I'm no photojournalist..either.
I disassembled my two(2) SR1911 - one unfired and examined all rails. All I see are uniform, very faint tool marks on all rails.
As to galling as I recall was a very early issue in SS semi-auto pistols. The reason given was that the same exact SS could gall. The early fix was to use dissimilar SS and the problem was solved. Since that was many, many years ago would guess that new SS have developed and one non-galling SS is used.
I'd lube the rails and shoot it, if it worsens or just makes you mad send back to Ruger.
I'm not a SR1911 collector..the second one is for my son's Christmas present.