BUENOS AIRES, Argentina — Argentine police hunted Wednesday for a 17th century painting which was allegedly stolen by the Nazis from a Dutch Jewish art collector and resurfaced this week in a property ad, only to disappear again. The painting, believed to be "Portrait of a Lady" by Italian baroque portraitist Giuseppe Ghislandi (1655-1743) was identified by the Dutch newspaper AD on Monday in a picture of a house for sale in the seaside resort of Mar del Plata. The authenticity of the artwork cannot be proven until it is recovered but it is believed to have been stolen from...