1972 Sobinov, unissued 10k (“Narodnyj Artist CCCP”), line perforated 12 1/4 (proof perforation, distinct from the actually printed stamp), with characteristic irregular perforations. Only a few of these proofs were prepared and affixed on special presentation sheetlets by Goznak. This stamp is never hinged but the gum is slightly disturbed, as a result of removal […]