AMSTERDAM Shielded from the public by glass panels and staring intently through microscopes, a team of specialists has started work restoring Rembrandt 's “The Night Watch ,” one of the most iconic paintings of the Dutch golden age. Eight art conservators are painstakingly removing multiple layers of varnish from Rembrandt's masterpiece depicting Amsterdam's civil guard on patrol. "Operation Night Watch," as their work has been called, is so difficult that they do not know when it will end at