2 Mark German Empire with letterpress imprint "Danzig", dark blue, rare color variant, horizontal pair from the lower margin with imprint HAN H3374. 20 and imprint plate number 4, postmarked "DANZIG-LANGFUHR f 21. 6. 21 10-11 V" timely strike not verifiable, unsigned, certificate Gunnar Gruber BPP (2014) "genuine and flawless", not listed in Michel, collector's item.