When restoring any "old" collectible, you always face the issue of what is your goal? To keep it as original as possible? To make it as usable as possible?
And, of course, we can always end up owning "Jim Bowie's knife".
The story goes that a kid shows up a school for "show and tell" with a locked box. He opens the box, and says, "this knife was Jim Bowie's personal knife, that he carried at the Alamo". The teacher asks, "This is the EXACT knife Jim Bowie owned?"
And the kid says, "Yes, this is the exact knife...but my great-grandfather did have to replace the old blade when it got rusty, and my grandfather had to replace the old handle when the wood started to rot...but other than the blade and the handle, this is the exact same knife Jim Bowie took to the Alamo..."