Official not issued: 15 piastre on 3 Mark violet black, overprint in type II \"A above with serif\", vertical type pair - upper stamp in base stamp type I and lower stamp in base stamp type II, mint never hinged, faultless condition, unsigned, photo expertize Ronald F. Steuer BPP \"in perfect quality. \", Michel 55.000.- - free of premium for the type pair, one of the largest rarities of all issues \"German foreign countries post offices and colonies\"