William Donato, a retired heavy- equipment operator from Altamont, searches for lost graveyards in his spare time. Donato, 64, enjoys scrubbing off the stones and seeing what he finds, like a treasure hunt. Donato is searching for cemeteries on a list of family plots on Guilderland farms that was published in 1940 by a local historian. An entry about the "Dunn farm at Dunnsville about 1000 feet southwest of the house, enclosed by an iron fence" led him to William Bennett's house on Route 20 on the western edge of Guilderland. Bennett, 69, a retired steamfitter, purchased the 36 acres in 1994 and a neighbor told him about the small cemetery with six graves next to a hayfield. An ornate wrought iron fence was in pieces. A decade ago, Bennett, his sons and some Boy Scouts cleared shrubs and opened up the cemetery plot. Bennett tucked the fence parts in his barn hoping to find time to repair them.