Re-Bluing = Ruint
I would only re-blue in the case of serious corrosion/deep pitting. I have tons of guns rubbed to the white, or blue turned brown with age (patina). To me that's part of it, even the hillbilly gunsmithing done on some of the old Whitneyville and Winchesters I don't try and correct, because they were just tools to the person who did it, but to me it's part of family history.
Unless Turnbull does it the value will drop precipitously, and even then it won't gain value.
I have four generations of guns under my stewardship. I won't sell any of them, ever. That said, I do know what each and every one is worth. If my kid or his kid wants to part with any of them they are gold coins in the safe, and I care about their value.