1924 10k on 5k green, wide "5" variety, l.h., v.f., cat. $1250 (Cat No. C7a) (Image)

Cat. $1250, Est.US$750

1924 15k on 1r red brown, surcharge inverted, l.h., v.f., signed NYSC, etc., cat. $1400 (Cat No. C8a) (Image)

Cat. $1400, Est.US$750

1930 Graf Zeppelin and "Complete five years in four", imperforate singles, l.h., v.f., signed Goznak, etc., cat. $3300 (Cat No. C12b-13b) (Image)

Cat. $3300, Est.US$1,000

1931 North Pole Issue, perf. and imperf., l.h., fine-v.f., cat. $369 (Cat No. C26-33) (Image)

Cat. $369, Est.US$150

1933 Balloon, 5k ultramarine, horizontal pair, imperf. between, canceled "Leningrad 1933", v.f., extremely rare, with 1988 Mikulski certificate (Zagorsky 341Pb) (Cat No. C37b) (Image)

Est.US$1,500

1933 Stratosphere Balloon, 5k indigo, imperforate trial color proof on watermarked stamp paper, unused without gum, some facial rubbing, otherwise fine, with 1994 Rossica certificate (Cat No. C37P) (Image)

Est.US$1,500

1935 Moscow-San Francisco 1r on 10k surcharge, used in 1935 on registered and flown cover from Moscow to Berlin, v.f., with arrival (23 Sep) pmk (Cat No. C68) (Image)

Est.US$1,500