That was over a 100 years ago with an almost new gun....what we have here is a gun that's well over 100 years old.

I'm sure it still holds true today if the deep pitt or hole is not in a high pressure area.
I shoot with a guy that has a Damascus barrel with a small hole in it that vents....it's close to the muzzle.

I'd go with the .99 cent vinegar solution....that way every time you pull the trigger you can just can keep telling yourself those pitts are not very deep...

Then wonder if they go sideways into the pattern welds ?