Leading purveyors of 20th century decorative arts, Two Zero C Applied Art and Historical Design, are selling off inventory this week in separate auctions while Art Nouveau specialists Jason Jacques and Lillian Nassau are adding mid-to-late 20th century collections to their galleries. Paintings dealer William Vareika sold a John LaFarge stained glass window (asking price: $500,000) to Yale University Art Gallery for the entry to its American decorative arts galleries, which is undergoing a renovation...