2 Mark German Reich with typography overprint "Gdansk", blackish blue, scarce colour variety, horizontal pair from lower margin with overprint HAN H3374.20 and overprint plate number 4, cancelled "Gdansk LANGFUHR f 21.6.21 10-11 V" used within the period of validity not to expertize, unsigned, certificate Gunnar Gruber BPP (2014) "genuine and immaculate", no quotation by Michel, collector's item