Issued in 1949 during the final months of the Republic of China's control, this mint never hinged block of six features a black surcharge of 100 Chinese dollars over a 50-dollar fiscal base stamp. The original issue, depicting industrial transportation motifs including a steam locomotive, passenger ship, and airplane, was printed by Chung Ming in Shanghai using lithography. Designed as a tax stamp, it was hastily repurposed for postal use amid rampant inflation under the Gold Yuan currency system. The blue design is sharp with clean lines, and the surcharge is uniformly applied. Printed on unwatermarked paper, the stamps measure 26 x 23 mm and are perforated 12½. Issued ungummed, this block remains in exceptional condition, showing excellent color and full selvage margins. It represents a transitional artifact between revenue and postal use in a collapsing economic environment. Scott 925. Estimate "$90 – 110"