I think you are seeing clearly, Daryl.
There is a great deal of difference between his fantasy goo and metal amalgam.
And that's fine.

And yes Daryl, we are discussing the restoration of function to a gun or rifle (within operating pressure limitations) with metal amalgam.

There are other ways to accomplish this.
Micro-welding is one way to do it. There are actually machines that can get in there and do the work with minimal-to none at all heat affected zone. The process is expensive and not for all applications.
Another way to go is to braze the affected area and re-cut the chamber - this way has greater heat affected zone.
Another way is to sleeve the chambers. This method can work, and some gunbuilders will do it. There have been discussions of catastrophic failures from this method, here (years ago) and on other double rifle sites.
Also there's the re-barreling approach, which is tremendously costly, and with a Damascus gun you can basically forget about finding Damascus replacement tubes.

There's also been the Teague sleeving process which essentially leaves the outer skin if the original tubes intact and full length sleeves are bonded in place.
I haven't heard anything of this process in the last few years. I wonder if the patent process is still available.

Mercury amalgam is basically a metal inlay process.
The resulting inlay is very tough with excellent compressive strength. This process, if it's actually viable (I'm willing to give it a test drive) is a cold process that doesn't require refinish to the barrels and won't affect regulation of a gun or rifle.
I know it's not fantasy goo.
It's ok with me if our friend here wants to maintain his position. More power to him.

Cheers
Tinker