EVENT: More than 2,000 visitors are expected to attend the fourth annual Bygone Farming Days at the University of California, Davis, as members of the Antique Mechanics Club roll out vintage farming equipment for a salute to the mechanical ingenuity of early-day California agriculture. A highlight of this year's event will be the Case tractor company's 150th anniversary celebration, including a tractor show and a statewide high school tractor restoration competition. Other activities will include a threshing bee, plowing contests, music, dancing, crafts, down-home food and plenty of children's activities. WHEN: Saturday, May 30, from 10 a.m. to 5 p.m. and Sunday, May 31, from 10 a.m. to 4 p.m. WHERE: Grain field south of I-80 at UC Davis exit, near Davis, Calif. VISUALS: Horse and ox plowing contest; vintage tractors, steam-powered threshers and other harvesting equipment; fiddling, square dancing and clogging; children's wagon rides, cow milking, butter making and bread baking; demonstrations by crafts people, including wheat weavers, a tinsmith and a blacksmith. COMMENTS: Preview photos may be arranged for by contacting Patricia Bailey, News Service, (916) 752-9843.