I wouldn't know about Jack in the Box or Stewart's as we don't have those in our area of Kentucky or if they were ever here they have long gone out.
Again when the franchises were bought they were bought as a KFC, why is that hard for you to understand? It would be the same if I bought into a Dairy Queen or Little Ceasar, you are buying a restaurant and using that name. KFC was sold in 1960's to John Y. Brown and he then ran it for a while. Almost all restaurants are a franchise with a person buying and using that name. Obviously it was a new concept to you as most of the KFC'S around here have been here longer than I have and long before 1964, according to one of the managers of the one that a friend's son works at. They just remodeled it because it was desperately needed.
The point was the franchise was sold as KFC, but the chicken was sold in an existing established restaurant, not their own. You don't have to own a building to own a franchise. Kinda like Carvel Ice Cream is sold in a supermarket or a Friendly's restaurant. They don't have their own stores anymore, but it is still a Carvel Franchise. Not a new concept.
They need more than remodeling. As I said before, there are very few left up north. The couple that are left share a building with Taco Bell or another restaurant owned by the same company.
When my wife sold her restautaurant her business and business name was sold separately from the real estate and building.