The damascus looks very good externally and of consistent wear. I suspect someone honed the inside and really worked out some pits in one area of the bore. I can't think of another way to get such peculiar readings from a gun. (I measured correctly and have an excellent wall thickness gauge)
No disrespect intended but I don't think you can tell anything by looking. We are only talking a few thousandths of a inch. The Hosford barrel wall thickness gauge measures outside wall concomitant with the inside. I think the only way to tell if the outside wall is out of round is to measure outside wall with a micrometer or caliper taking several measurements. You might be right but I think the outside wall being out of round is a possibility too as these old boys used files to strike up their barrels.
