My $0.02 worth of conjecture and opinion
I doubt a gunsmith at G&H ever measured wall thickness on your gun. Without knowing the depth of the defect before honing, it's impossible to speculate if the pits were that deep, or someone got carried away at the hone. I'll further guess it was a consignment* gun.
If Orvis measured the wall thickness at all, it was after the other work was completed. They might have been a bit sheepish to report (borderline) wall thickness when they just completed $800 in barrel repairs (as opposed checking them prior to quoting the work).
Turnbull's, probably same as Orvis.
*When I was in the business 10 years ago, more often than not, guns were taken on consignment because the owner rejected a reasonable cash offer. Antique consignment guns were taken in, chokes, stock dimensions recorded, and handed over to the gunsmiths to be looked over. That was about it. Occasionally, they would reject a gun for a fault I missed.
Again, 10 years ago dealers rarely, if ever listed wall thickness in an ad. That info was provided if requested, but I never measured or cleaned a consignment gun unless requested or something looked out of sorts. Seems to me, the larger issue lies in what thickness is "safe" at what point, for which gauge, for what steel, at what round count, yada yada yada... anecdotal testimony abounds. Without proof laws, it's caveat emptor (squared) when buying old guns to shoot.
Is it safe? Past performance is not indicative of future results.
Were it me, I'd request a sit down at G&H and see if they will help you recover some part of your current or future (sleeving) losses. They've always been a top drawer outfit.
Good Luck
