The counter at DeLuca’s Diner runs long and straight, facing a short-order cook and an open kitchen that’s put on a show nearly every morning since 1951. The “new” dining room, open nearly as long, features rows of lime green and lemon yellow booths and a signature Grecian mural painted as the backdrop for one of the many movies filmed there. Founded by two brothers and sold to completely new ownership just once in its history, DeLuca’s stands as the second-oldest continuously operating restaurant in the Strip, behind only Primanti Bros. Henry DeLuca Jr. — whose father, Henry DeLuca Sr., and uncle Vince DeLuca opened the restaurant — traces its roots to Lucca, the Tuscan city where his paternal grandparents were born. That shared hometown mattered in midcentury Pittsburgh in neighborhoods such as the Strip District, where Italian and other immigrant families still relied on dense social and working networks. “The common theme is that city in Italy,” DeLuca says. “There were a lot ...