Despite 20 inches of snow in Central Park, the New York Stock Exchange kept normal hours today, allowing the Dow to shed 18 points at close.  The Manufactured Housing Composite Value, however, rose more than two percent. Benefitting most were Nobility Homes, Cavco, up nearly three percent and Skyline Homes which added more than one percent for shareholders. Drew Industries and Universal Forest Products were also up for the day. Sun Communities and UMH Properties closed down.