THESE stylish Philadelphians of a certain age possess what I call "advanced style." They exude a long-forgotten sense of class in which men and women dressed more for style than comfort. These seasoned ladies don pearls, dress hats, Chanel bags and kitten heels on their feet. The mature guys are sporting facial hair, classic navy sport coats, vintage eyeglass frames and Belgiumloafers. Their style, like fine wine, just gets better with age.