U.S. & Worldwide Stamps & Postal History

1911 50s ochre and black, center inverted, cancelled Plovdiv June 13, 1913, v.f., signed Herbert Bloch, Karaivanoff and Mikulski, with their 1935 and 1985 certificates. This major error occurred as the bicolored set was printed first in one color and then passed through the press again for the second time. While a premier rarity of Bulgarian philately, this error actually went unnoticed by the public for seven years, the first example being discovered in 1918 by a Nicola Kochanov in Sofia. All of the known (only about 30) examples are used (Mi.86K)
Cat. Val. €7,500
Estimate: $5000