Canal Zone February 1929 2c Carmine Canal Zone Seal with Air Mail overprint (Scott #UC2/UPSS #A5) entire with 1929 25c on 2c carmine (#C3, VF), tied by BALBOA HEIGHTS, 3-8-1929 machine cancel to U.S. with Cristobal (3-9) transit backstamp. Horizontal blue and red bars and "VIA AIR MAIL" at left on #U9/10. "AIR MAIL / 25 CENTS 25" surcharge on 2c Goethals #106. Very Scarce Commercial use of two part 25c plus 2c rate which was only in effect for 38 days in which there were only four flights from Cristobal to Miami. Attractive and Important Early Airmail Postal History from the Canal Zone to the US.