A DECADE OR so ago, Nicholas Ward-Jackson woke up one morning determined to get out of Venice. After nearly five years, the English art dealer and his wife, Margherita, an Italian psychotherapist, had outgrown their small home and were tired of the tourists. But the day before their scheduled return to London, where they have another residence, Ward-Jackson, now in his 80s, received a call from a real estate agent cousin of Margherita’s about a listing in Dorsoduro, a more intimate neighborhood separated from the crowded cafes of Piazza San Marco by the Grand Canal. Reluctantly, he agreed to tour the property: a 3,500-square-foot apartment on the piano nobile, or second floor, of a 17th-century palazzo.
