Well here's my two cents. Just to clear up one piece of misinformation, not all pins are case hardened. In guns with removable end caps where I have actually removed the pins none of them were case hardened, or at least didn't appear to be. It was also impossible to tell if they were worn as I didn't know the original diameter, they showed wear but was that from the maker sticking it in a lathe for a little polishing??At any rate if you don't remove the pin you'll just be guessing at it's condition. Obviously, guns can be tightened in a variety of ways, how you do it depends on what day it is, or how much time and money you want to spend, or maybe even your skill level,whatever. Nevertheless, the best possible condition is when the pin is perfectly round and polished and engages the hook all across it's width and over it's entire contact area. If the hook and pin are polished mirror bright, in perfect contact and the gun closes tight as a bank vault, why then you've got a gun that will give the longest use. I don't know Mr. Eversull except for his great reputation and having spoken to him by phone, but unless he can walk on water and also turn it into wine he cannot achieve what I've just described without removing the damn pin. I've got no problem with shimming a hook, welding it, using scotch tape or chewing gum. All are better than shooting a loose gun. But if you want the best it's best to know what's best.
