3 Kopeken Workers, handstamped "Eesti Post", block of four with two overprint tete-beche pairs, upper stamps with inverted overprints, cancelled "ELVA + EESTI + B 14.VIII.41", perfect condition, Thilo Nagler VP expert opinion (2025) "genuine and faultless", Mi. 3.600.- (less than four singles including inverted overprints = 3.700.-)