Part 1 of 3 in Hartford, Conn., visits Mystic Seaport, a maritime museum, for a look at its collection of rare paintings. Appraised items include a 1963 poster for a Joan Baez-Bob Dylan concert at New Haven Arena; a pair of 18th-century silk shoes said to have been worn by a dance partner of George Washington; and 200-year-old Wedgwood pottery buttons.