Christie's experts got a surprising e-mail from a man in Argentina. He wondered if the hand-carved Canada Goose that sat on his parents' mantel for decades had any value. Turns out the piece was part of a rare 19th-century working rig that once plied Pennsylvania's Susquehanna River before being found and dispersed in the 1920s and 30s. Scheduled for the auction block on Sept. 30, the white pine bird carving is conservatively estimated at $200,000 to $400,000. Another bird from the rig was sold by Christie's for $553,600 in 2007. The carver is unknown.