Panama, 1926 (May 24) Colon to Almirante Survey Flight, group of six covers with all-different frankings carried on the survey flight, each with purple "Via Air Mail" straightline and blue Almirante (5.25) arrival duplex, frankings include #197 pair, 199, 209, and three 1924 Arms Issue covers with ½c block of four (234), 1c pair (235) and 2c (236), Very Fine, Only 20 covers were Flown on this Survey Flight.. Estimate  $400 - 600. $0 (Image)