1939 Macau airmail stamp ovpt. “Exposicao Internacional Nova York” 50a, with inverted ovpt variety (Yang U2b). MNH with a toning spot
1939 Macau airmail stamp ovpt. “Exposicao Internacional Nova York” 50a, with inverted ovpt variety (Yang U2b). MNH with a toning spot on reverse. With RPSL COA.1939年澳門大葡帝國航空票5毫加蓋“紐約世界博覽會”新，帶加蓋倒蓋變異（楊目U2b），原膠無貼，背面帶一小黃點。附皇家郵學會證書。
