DUDLEY fRASIER, who worked in a variety of publishing positions, most recently as editor-at-large at Pocket Books, died May 2 after a brief illness. He was 75.Frasier began his publishing career at Little, Brown in Boston, where he became publicity director. Moving to New York, he worked for Rinehart before becoming executive editor at Popular Library and New American Library. He was then an editor-at-large at Pocket until his retirement.