50 C. Mercury Head horizontal pair, overprint type II, stamp-sized blank label attached at right, usual "Coudekerque-Branche" mark on reverse, mint never hinged, perfect condition, printing only 1.500 pairs, only c. 300 possible with label; most issued stamps of this value used for franking, mint never hinged blank-label multiples rare, signed Brun, Lothar Herbst VP expert opinion (2024) "Condition faultless.", Mi. 1.800.-