I had overlooked one significant detail about the New York pot. The amphora was published by Dietrich von Bothmer, "Greek and Roman Art", Recent Acquisitions (Metropolitan Museum of Art), (1985 - 1986), p. 9 [JSTOR]. It was purchased by the Rogers Fund, the Classical Purchase Fund, and The Vincent Astor Foundation Gift. The published photographs show that the amphora had at some point been broken and then reconstructed.
Images of the amphora were seized from the premises of Giacomo Medici in the Geneva Freeport. Peter Watson and Cecilia Todeschini (The Medici Conspiracy, p. 107) commented:
Then there were the photographs of a red-figure Attic amphora by the Berlin Painter. Among the photographs seized was one showing this in the early stages of restoration, with the fragments crudely assembled but with many gaps. A second photograph shows the amphora after complete restoration, "in near perfect conservative condition thanks to expert restoration which completely eliminated the traces of breakage."Who was the conservator?
When the vase was acquired it lacked only a handful of small fragments. Shortly after it was placed on exhibition, Dr. J. Robert Guy recognized that nineteen of the fragments had been in his collection for some time. He has graciously donated these fragments (1985.315) to the Museum in "Commemoration of the Centenary of Sir John Beazley's Birth."
The Beazley Archive database does not appear to include the information about the additional fragments. When did Guy acquire the pieces? What was their source?
Such questions are also relevant to the issue of the acquisition of pot fragments (formerly owned by J. Robert Guy) by the Harvard University Art Museums in 1995.