PREVIEW

Sotheby's staff members stand by 'The wings of an altarpiece: Wilhelm von Schwendi (d. 1522); Barbara Krafft von Dellmensingen (d. 1538)' by Bartholomäus Zeitblom, estimated at 400,000 to 600,000 GBP, during the photocall for Sotheby's Old Masters Sale in London.