The lustrous oiled leather, gleaming hardware and colorful surcingle webbing of the saddlemaker's art have been transformed into this year's most popular sporting accessories. The horsy look has not sprung up overnight. Chanel's legendary tweed suits have long been harnessed by chain belts. And Europe's two famed leather-goods houses, Herm�s of Paris and Gucci of Italy, have used equestrian devices on their luggage, scarves, belts and shoes as long as they have been in business. But suddenly the hitched-up look has become a kind of cult. The trappings of the cult are arranged in the tack-room display in the photograph at left. The ladies' ring belts are all taken from designs found in a horse-hardware catalog (the heavy link-chain belt is of 14-karat gold). The webbed belts for men and women are made of actual surcingle strapping. The man's moccasin, with a miniature snaffle bit across its instep, is made by Gucci in Italy and costs $49 in New York, but Gucci's Fifth Avenue shop can hardly keep them in stock—it sells 300 pairs a month. The vinyl boots, the silver loafer and the No. 3 shoe with the horseshoe on the vamp are all made by Herbert and Beth Levine, shoe designers who get their inspiration from their own racehorse. The saddlebags, scaled down to hang on a lady's shoulder, are the sporting handbags of the season. The trophy is not for sale but is equally coveted; it is the Triple Crown for fillies.