I've had Andys Custom Shop re-lay ribs on several of my shotguns to make them whole again. The first job was to repair the screw up of another "gunsmith" who reblued the barrels of one of my O/U clays guns. The problem was that the first guy either didn't notice that the barrels were soft soldered or he didn't care. I'm not sure which was the case but that was a lesson I didn't really want to have to afford at the time. The other "big" job was when Andy rebuilt/restored my 21 which had the ribs patched long before I bought the gun. That had a fair amount of pitting and rust under the ribs where the old repair was.
After seeing the issues with my shotguns that good gunsmiths have sorted out I'm of the opinion that it's money well spent to have only good people work on my guns. I may have to save to have the work done but in the end for me at least it's more economical to not have to worry if the job was done right the first time.
I may still have some photos of the 21 barrels posted on the hunt 101 site that show the pitting and rust but it's been months since I've actually been on there so I'm not sure.
Parris George