拍品專文
The base inscribed O.B. 510 in black ink.
See G. Zick, ibid., p. 211, where she cites two other known examples as Kat. nos. 131 a and b, both of which are impressed with the same numerals as the present lot.
See G. Zick, ibid., p. 211, where she cites two other known examples as Kat. nos. 131 a and b, both of which are impressed with the same numerals as the present lot.