This 1941 wartime issue from Japanese-occupied China presents a striking overprint on the original 5 cent Dr. Sun Yat-sen definitive stamp, revalued to 3 cents. Printed in green olive and featuring the well-known engraved portrait of Sun Yat-sen, the stamp was produced by Dah Tung Book Co. using gravure printing on watermarked paper with a small multiple "YU" character pattern, and is perforated 14. The series reflects complex geopolitical tensions during the Second Sino-Japanese War, when occupying forces reissued Chinese stamps with surcharges to assert administrative control over the postal system. Despite the adversity of the times, the continued use of Sun Yat-sen's image symbolized enduring Chinese nationalism. The block comprises ten mint never hinged stamps, each with variations in overprint placement and calligraphy, characteristic of localized wartime production. These stamps are catalogued as Michel CN-IM 389, Scott CN-IM 446f3, Yvert et Tellier CN 332A, Stanley Gibbons CN-IM 581b, and China Stamp Society CN-IM 569. Condition: Mint never hinged group showing strong gum and crisp color, minor offset and uneven inking typical for the issue. Estimate "$75 – 90".