Richard Searls is a warrior among documentarians. He has an indent on his forehead from getting bumped with a tripod leg and a tattoo of a rosebud on his hand, a reference to “Citizen Kane.” Most famous for “Dead River Rough Cut,” a film he made with Stu Silverstein about two trappers living in the backwoods of Maine, Searls has produced and shot hundreds of films. In late January 2013, the unthinkable happened: A fire destroyed his farmhouse and took with it a lifetime of master reels, recording equipment and negatives.