1918 opt Bosnia Postage Due set 2h-3K with the alternate Roman & Cyrilic opts swapped with Roman opt on 2h, Cyrillic opt 4h etc. VF fresh M/MLH. SG D19-31(var), Mi P1-13(var). 2012 Prof Bilandzic photo cert. Rare error set. (13) (P)

Estimate AU$250