Kutter
I'm assuming you are an engraver, and therefore the first to notice such minute details; which details I can't address other than to say that in my study of the L C Smith gun, I've seen my share of miscues and inconsistencies. As to the rib matting, it is impossible to determine exactly what it is we have there until such time as we see a pic of the rib/rib joint area. I've seen a few instances whereby a small area of engraving was placed ahead of the gold bar inlay, then machine matting from that point to the end of the rib; perhaps this is one of those instances? But as Smith gun rib matting is not nearly as pronounced as many other makers, I'll stick with my theory that what little we see is indeed standard machine matting; then, assuming we see good pics, either feast or eat crow afterwards. The Smith gun example we see here is not markedly unique; but allow me one final comment about pre-1913 Smith guns and I'll shut up. Anyone who has ever spent a lot of time studying pre-1913 Smith guns will tell you that it is not uncommon to find significant differences between guns of the same grade, find graded guns with engraving scenes markedly different from cataloged grade depiction; and other guns with no assigned grade, and engraving patterns outside any standard catalog grade format/description. A few such guns have been featured in the DGJ; and it is only the discovery of these unique Smith guns that keeps me interested in the "sport".