My point was pretty much that 80 year old solder is 80 year old solder, Larry. If a soldered rib comes loose on a pump, you can just chisel the thing completely off and keep hunting-it isn't structural, like it is on a NID, or any other double. The first pump gun ribs, ala' the Remington 17 and 31 were integral with the barrel. There was no solder to fail.
The Achilles heel on a double is always the barrels. They are the most beautiful aspect, and weakest element of a double gun. It is extremely old school repeating technology, that the pump, and, later, the autoloader eclipsed.
The NID barrels are a complete rework of what? The barrels were still tinned and held to the rib with the same mix of lead and tin as had been practiced since the middle 1800s.
John Olin was having a hell of a time figuring out how to get the chromoly steel his model 21 used wetted with solder in use at the time, and didn't need any more bad publicity then he already had with model 21 lugs coming loose to screw with a magnum model 21 at the time. He knew he had a problem.
A lot of people today realize he had a problem, too.
If nobody bothers to teach you otherwise, it is OK to be 26 and think you have to slam a double to shut it. I've seen much older examples doing the same. Most folks are instructable, either by teaching, or a spendy repair bill.