New York and Curatorial Responsibilities

"In the event that a third party brings to
the attention of a member museum information
supporting the party’s claim to a Work, the museum
should respond promptly and responsibly and take
whatever steps are necessary to address this claim"
AAMD Guidelines:

Christos Tsirogiannis has spotted a suspect Medici vast at the Metropolitan Museum (David Gill, 'A Paestan krater in New York and curatorial responsibilities', Looting Matters, May 30, 2014). A Paestan krater is likely to have been found in one of the cemeteries around Paestum, what is its collecting history?