Cherrystone Auctions note: "RUSSIA Air Post 1924 10k on 5r green type II, basic stamp wide "5", complete pane of 25 showing diagonal shift of surcharge, never hinged and post office fresh, natural gum creases and gum skips at bottom right, each stamp with a double "Goznak" handstamp on back, also signed in pencil and by Mikulski. A major museum-quality rarity from the Soviet Union, ex-Mikulski collection. Of considerable Air Post and world-wide importance, undoubtedly unique! (Standard Cat. $105,000+ for singles). Price Realized: $700,000.00."