1931 50k violet brown (instead of dark brown), imperf. horizontal pair, pos. 7-8, cancelled to order as always "Tula 28.4.43", handstamped "D", with 1997 Mikulski certificate. A major color variety from the Soviet Union, only 24 issued (Mi.400GbC) (Liapine 334 P1, Euro 20,000) (Cat No. C18var) (Image)

Est.$7,500

1932 15k gray black, 25 sheets of 40 (1,000 stamps), n.h., fine-v.f. (Zagorsky 301, $16,000, Zverev 304, $25,000) cat. $12000 (Cat No. C25) (Image)

Cat. $12000, Est.$3,000

1932 15k gray black, perforated 10 1/2, entire sheet of 40, cancelled to order "Roshal Moscow 17.7.1933," with full original gum (never hinged), fresh and fine-v.f. Multiples of this rare perforation are virtually non-existent; this is probably the only sheet still intact. A fabulous rarity (Cat No. C25a) (Image)

Est.$5,000

1932 15k gray black, imperf. left sheet margin single, l.h., v.f., signed Stolow, only 100 printed (Cat No. C25c) (Image)

Est.$3,000

1932 International Polar Year, set of two blocks of four, n.h., v.f. (Zverev $2,250) (Cat No. C34-35) (Image)

Est.$1,000

1934 Civil Aviation (watermarked), 20k carmine, right stamps perforated 13 3/4:10 1/4:13 3/4:13 3/4, right sheet margin block of four, n.h. and post office fresh, v.f. A splendid rarity, only a few examples of this compound perforation exist, rare combination block of four (Cat No. C42var) (Image)

Est.$20,000

1935 Chelyuskin, 1k-50k blocks of four, complete set, n.h. and post office fresh, unfolded and in absolutely perfect condition, very fine (last auction realization recorded by us was June 2012, where a similar set realized $65,000 plus buyer's premium) (Cat No. C58-67) (Image)

Est.$25,000

1939 Overprints, set of five blocks of four, n.h., v.f. (Zverev $750) (Cat No. C76-76D) (Image)

Est.$300