It isn’t every street that, just by virtue of its name, conjures up a particular way of life. But ever since most of Fourth Avenue was renamed for the planted medians in the center of the boulevard, “Park Avenue” has been shorthand for traditional Upper East Side wealth and privilege. Case in?point: an apartment in a 1926 building by Schwartz and Gross. “The layout was old-world. Very front-of-house and back-of-house,” Taryn Christoff of Christoff Finio Architecture says.