But this too is probably a false picture. This town, like Isabel and maybe Aurelia, shares its name with debutantes—the daughters of Percy, the transcontinental tycoon. In pictures, Percy A. Rockefeller’s thick jowls and small worried eyes remind you of a picture book. Right there on the shelf in the TV room: Percy the Small Engine (1956), about a shape-shifting locomotive who sometimes prefers the look of...