WHAT’S HAPPENIN’ FRIDAY, APRIL 15 ‘Fabulous Fridays’ Begin For Season In Oneonta HISTORICAL ARTS — 2 p.m.-10 p.m. (also 9 a.m.-10 p.m. April 16 & 9 a.m.-noon April 17). Free public exhibition and demos at Historical Society of Early American Decoration’s 70th anniversary “Coming Home” conference. 2 p.m. Friday appearance by Ken Farmer, of PBS’s “Antiques Roadshow.” Ticketed dinner banquet with British decorative art expert Yvonne M. Jones. The Otesaga, 60 Lake St., Cooperstown. Info, tickets, (607) 547-5667 or info@hsead.org ART…