1930 Five Years in Four, 40k and 80k imperforate singles, l.h., v.f., cat. $3300 (Cat No. C12b-13b) (Image)

Cat. $3300, Est.$1,500

1931 North Pole, imperforate blocks of four, l.h., v.f. (Zverev $4,000) (Cat No. C26-29) (Image)

Est.$1,000

1933 Stratosphere Balloon, 5k indigo blue, ultramarine, dark brown, three different imperforate and gummed trial color proofs on watermarked stamp paper, h.r. or l.h., v.f., last one signed Mikulski. A rare group (Zverev $18,000) (Cat No. C37P) (Image)

Est.$10,000

1935 Chelyuskin, complete set, h.r., fine-v.f., cat. $1032 (Cat No. C58-67) (Image)

Cat. $1032, Est.$500

1935 Moscow-San Francisco 1r surcharge on 10k Levanevsky, used on registered and flown cover from Moscow (22.9.35) to Berlin, v.f., with arrival pmk on back (Cat No. C68) (Image)

Est.$500