Dick; I worked as a machinist for 35 yrs & have been around both processes, but never saw a damascus or twist bbl checked. I know where this crack is, but it is not open & definately not evident. I doubt many could find it even if told it was there. My thinking was that even if the MT process picks up on the welds, this spot would stand out much more prominent, but I could be wrong. Not trying to be argumental, incidently, but to discuss what will & will not work.
I Didn't Say Everything I Said, Yogi Berra