This 1943 issue from the Japanese occupation of Central China features a black overprint reading "30 圓" on the 2 fen dark blue stamp originally issued as part of the Martyrs series (CN323). The overprint was applied to reflect the inflated local currency during wartime administration under the Japanese-controlled Reorganized National Government. Printed by Commercial Press Ltd., Hong Kong, using gravure, the stamp has no watermark and exhibits variable perforations typical for occupation-era printings. The design retains the formal portrait of a revolutionary martyr framed by laurel and sun emblem, with overprint text placed vertically and the surcharge in a framed box at bottom center. This block of four is mint never hinged with full original gum, strong impressions, and precise centering. The issue is cataloged as Scott IM 9N75, Michel JP-CC 71, Stanley Gibbons JP-CC 91, Yvert CN-OJ 66, and China Stamp Society SN105. As an example of occupation postal overprints, it holds both historical and philatelic value for collectors of WWII-era Asia. Estimate "$120 – 140"