PARIS, FRANCE.- Art reporter and critic Stuart Preston, 89, died in Paris. He studied at St. Paul's School in Concord, N. H., and Yale. He did postgraduate work at Columbia, Harvard and New York University. He also worked briefly as a curator at the National Gallery of Art in Washington. He was attached to the intelligence section of Gen. Dwight D. Eisenhower's staff during the war. After the invasion of France, he was assigned to the Arts and Monuments Commission, to track and identify works of art looted as war booty. He received the Croix de Guerre for his work from France.