2 Mark German Reich with letterpress "Danzig" overprint, blackish blue, rare shade variety, horizontal lower sheet margin pair with overprinted job number H3374.20 and overprint plate number 4, cancelled "DANZIG-LANGFUHR f 21.6.21 10-11V", contemporaneity of cancellation unverifiable, unsigned, certificate Gunnar Gruber BPP (2014) "genuine and faultless", no Michel quotation, connoisseur's item.