NEW BEDFORD — A museum has restored the longest painting in North America so it can share the story of American whaling with the public.The quarter-mile-long (0.4-kilometer-long) panorama toured the U.S. after it was completed in 1848. A section was featured at the 1964 New York World's Fair.But the panorama deteriorated after so much traveling on wagons and trains, rolling and unrolling.