1924 10k on 5r green, basic stamp wide "5" variety, light cds, v.f., signed Mikulski, etc., cat. $700 (Cat No. C7a) (Image)

Cat. $700, Est.$250

1924 15k on 1r brown, surcharge inverted, l.h., v.f., with handstamped guarantee mark, v.f., cat. $1400 (Cat No. C8a) (Image)

Cat. $1400, Est.$1,500

1924 20k on 10r carmine, surcharge inverted, Moscow cds, v.f., signed Mikulski, Dr.P.Jemchouhin, rare and undercatalogued variety, cat. $2500 (Cat No. C9a) (Image)

Cat. $2500, Est.$1,500

1930 Zeppelin 40k and 80k imperforate singles, h.r., the latter creased at top margin, signed Bartels, the latter Goznak handstamp, v.f., with Dr.Leupold certificates, cat. $3300 (Cat No. C12b-13b) (Image)

Cat. $3300, Est.$1,500

1931 50k violet brown, imperforate trial color proof on gummed stamp paper, large margins all around, l.h., v.f. A significant Soviet and Air Post rarity, only 24 (!) recorded, this one being position 15 (indicated in pencil), with "D" Postal Museum handstamp on back, 2016 Buchsbayew certificate (Sanabria 40) (Liapine 334P1) (Cat No. C18var) (Image)

Est.$5,000

1931 50k violet brown, imperforate trial color proof on stamp paper, large margins all around, canceled TULA, v.f. A significant Soviet and Air Post rarity, only 24 (!) recorded, this one being position 2 (indicated in pencil), with "D" Postal Museum handstamp on back, 2016 Buchsbayew certificate (Sanabria 40) (Liapine 334P1) (Cat No. C18var) (Image)

Est.$5,000

1931 50k gray blue (error), l.h., exceptionally well centered, v.f., cat. $500 (Cat No. C23a) (Image)

Cat. $500, Est.$250

1931 50k gray blue (error), l.h., exceptionally well centered, v.f., cat. $500 (Cat No. C23a) (Image)

Cat. $500, Est.$250

1931 50k gray blue (error), block of four, n.h., well centered, v.f., with 2010 Raritan guarantee. A rare multiple (Cat No. C23a) (Image)

Est.$7,500

1931 50k gray blue (error), used, exceptionally well centered, v.f., cat. $300 (Cat No. C23a) (Image)

Cat. $300, Est.$150

1932 Polar Year, set of two used on cover from Leningrad (11 Aug 39) to USA, fine-v.f., scarce commercial usage on one cover (Cat No. C34-35) (Image)

Est.$150

1934 Civil Aviation Issue, with and without watermark, n.h., fine-v.f. sets, cat. $1220 (Cat No. C40-49) (Image)

Cat. $1220, Est.$300

1934 5k violet brown, perf. 14, n.h., v.f., signed Diena, etc., cat. $275 (Cat No. C50a) (Image)

Cat. $275, Est.$150

1935 Chekyuskin Rescue, complete set, n.h., post office fresh, few values with sheet margin, v.f., cat. $2048 (Cat No. C58-67) (Image)

Cat. $2048, Est.$1,000

1935 Moscow-San Francisco 1r on 10k dark brown (Levanevsky), two copies, one lower case Cyrillic "f", l.h., v.f., signed Goznak, Diena, etc., cat. $2225 (Cat No. C68,68b) (Image)

Cat. $2225, Est.$750

1935 Moscow-San Francisco 1r on 10k dark brown (Levanevsky), lower case Cyrillic "f", n.h., v.f., signed Diena, cat. $2250 (Cat No. C68b) (Image)

Cat. $2250, Est.$750

1935 Moscow-San Francisco surcharge, lower case "f", used, v.f., signed Goznak, etc., cat. $1450 (Cat No. C68b) (Image)

Cat. $1450, Est.$500