10 Rbl. on 1 Rbl dark blue, vertical pair with normal and inverted overprints (t?te-b?che), faultless mint never hinged! unsigned! certificate Zirath BPP (2025) "The condition is faultless ... These stamps are among the greatest rarities of the German occupation issues of World War II.", Mi. -.-, a single off-cover stamp with inverted overprint alone already 15.000.-