Some diners said they considered Sette Mezzo’s owners and staff to be something like family. Reached on her cellphone, Barbaralee Diamonstein-Spielvogel, a preservationist and Democratic fund-raiser, spoke lovingly of Mr. Mania, whom she described as “the ambassador from Friuli.” She paused to say goodbye to her driver and explained that she was at the airport in North Carolina and on her way home. “I was at Duke University, where they’re going to establish, I’m ashamed to tell you, the Barbaralee Diamonstein-Spielvogel video archive.”