At Colonial Williamsburg, getting the period details just right is a mission for furniture conservator Leroy Graves. Over the past three decades he has revolutionized how museums preserve and protect upholstered antiques, despite this son of sharecroppers having had virtually no formal education. A detective of sorts when it comes to repairing and refitting antiques, Graves' work is featured in an ongoing exhibition called "Upholstery CSI." Martha Teichner reports.