Thunks (sorta) Who do you recommend?

[B. Dudley]

Dean, what is an Eand? Just kidding.

John,
It sounds like you have a little bit of an issue there with your barrels. And by the sounds of it someone has already been into them to attempt a repair.
A dull sound is not always a telltale sign that the ribs are loose, but it is a red flag telling you to look closer. I have come accross barrel ribs that were loose and you would swear they were tight by looking at them. And when taken apart, there was about 10" worth of rib that had almost no solder holding them together. Not every factory solder job Is perfect and completely void free.

As a rule of thumb, the only way to properly fox a loose rib is to remove it completely and relay it.

And a tip for checking for loose ribs. Put some oil in the cracks of the ribs and let it sit for a minute. Then wipe it out. Then in the light, push down / squeeze on the rib firmly. If it is loose, you will see oil movement as it pushes out from under the rib in the light.