FBI agents, bloodhounds, beagles and a ferret are swarming the backyard of a reputed Connecticut mobster hunting for the long-lost Gardner Museum masterworks, the alleged gangster’s lawyer told the Herald this morning. Agents are executing a search-and-seizure warrant to look for guns at the Manchester, Conn., home and property of 75-year-old Robert Gentile, but “they’re looking for paintings,” said defense attorney Ryan McGuigan. “We all know what they’re really looking for.