Auction #93 Worldwide Air Post stamps and postal history, Zeppelin Flight items, philatelic rarities of the World

1913, Tercentenary of the Romanov Dynasty, Nicholas II, late stage proof of 5r in reddish brown, design with complete engraved hatching, including thickened corners of ''5 roubles'' and engraving at the bottom of the oval, but unfinished cleaning of the design, printed on wove paper, size 70x92mm, marked in pencil with ''14'' at top right, no gum as produced, VF and very rare, Est. $1,500-$2,000