10 Rbl. On 1 Rbl dark blue, vertical mint never hinged pair from normal stamp and inverted overprint, certificate Zirath BPP (2015) "the mint never hinged stamps in the vertical pair. . Have in each case an authentic overprint. By of the lower is the overprint inverted. The stamps have full original gum. The condition is perfect. . . This is the fourth known copy. " Michel -.-, for a single stamp with inverted overprint 15. 000.- EUR.