At the risk of opening a hornet's nest, in response to the OP's question those Perazzi bbls. might lend themselves to becoming a 'carrier barrel' for a set of tubes or even being chamber sleeved in the case of the affected barrel.
W/o seeing it and doing a bit of measuring one can't honestly evaluate it's 'salvageability' or 'repurposing' for either application/remedy. I do know of guns treated in both manners that continue to provide good service target shooting. Just saying its worth having a party who does such work evaluate it and go from there.
As to bulges removed from the chamber area, I have a 28ga. O/U that came back from a loan for someone to shoot dove w/in the late 60's that somehow got a bulge in it's lower bbl. roughly 6" back from the muzzle & in front of the forearm. The side ribs were not loosened. I have shot it that way since and still do and the gun has digested hundreds, if not a couple of thousand or more rounds since usually through that same bottom bbl. being fired first. Does it bother me? Of course, if I think about it and that it happened. It wasn't intentional, I know that. Am I concerned from a safety perspective? Not in the least. It's a 26" IM/F Charles Daly Superior grade Miroku and its still a delight to shoot dove with. Value was degraded, not the utility. 'Nuff said.
