The Berlin painter krater fragments in Malibu

I have noted the return to Italy of a fragmentary red-figured krater attributed to the Berlin painter. The fragments were donated sequentially.

The earliest fragments were donated in 1977 by Herbert Lucas (inv. 77.AE.5), followed by a gift of Vasek Polak in 1982 (inv. 82.AE.124.1-42). Dietrich von Bothmer gave eight further fragments in 1984 (inv. 84.AE.972.1-8) [JSTOR] [no. 22], and two other pieces were sold from Galerie Nefer ("European art market") in 1984 (inv. 84.AE.68) [no. 21].

One of the other sellers of a fragment was Frederick H. Schultz, Jr. who was associated with Jonathan Tokely-Parry. He sold his fragment in 1987 (inv. 87.AE.51), though the J. Paul Getty Museum recorded it as a donation by Bothmer [JSTOR].

Fifteen further fragments were added in 1990 from the "London art market" (inv. 90.AE.2.1-15) [JSTOR]. A further set of loans was made in 1989 (L.89.AE.43.1-3, 5, 7, 9, 10, 13-15, 20, 23, 24, 28, 30, 39).

Peter Watson has commented on these fragments in The Medici Conspiracy: "In the case of the Berlin Painter krater,  the bulk [of the fragments] came from Symes, quite a few came from Dietrich von Bothmer, a few came from Nefer Gallery, and one from Fred Schultz" (p. 227). Watson also implies that the the loan of fragments was made by Giacomo Medici who had offered to sell them for $125,000 (p. 225).

Where did Bothmer acquire the fragments that he presented?

Bibliography
Moore, M. B. 2000. "The Berlin painter and Troy." In Greek vases in the J. Paul Getty Museum, vol. 6: 159-86. Malibu: The J. Paul Getty Museum.
Gill, D. W. J., and C. Chippindale. 2007. "From Malibu to Rome: further developments on the return of antiquities." International Journal of Cultural Property 14: 205-40.