After more than 100 years in the Metropolitan Museum collection, nearly 200 19th-century plaster casts of classical sculptures and architectural details go on the block at Sotheby’s New York on Feb. 28, 2006. On view in a special study gallery at the Met until the 1950s, the casts are now in a state of fashionable dishabille -- and are being offered without reserve. Who might want them? Decorators, perhaps, or collectors with an empty hall or two. Among the items are casts from the pediments of the Temple of Zeus at Olympia, reliefs from the Parthenon and the Pergamon Altar and the Cathedral of Notre-Dame in Paris.