Radio historian  J. David Goldin  was browsing for archival audio on eBay one night when he stumbled into something strange: A 1937 radio interview of baseball great Babe Ruth. It seemed remarkably like a recorded interview Goldin had donated to the National Archives more than 30 years ago. Goldin started sleuthing. His detective work led him to Leslie Waffen, a longtime official at the National Archives. Waffen eventually admitted to stealing nearly a thousand recordings. Yesterday, Waffen was sentenced to 18 months in prison.