1936-1947 group of 50 first flight covers, franked with #C8, C9 includes scarce flights such as 20 examples of July 1, 1947 flight (the Revised Transcontinental flight), 13 examples of the Oct 1-2 flights, etc. (Image)

#C1 5¢ imprint plate block of six, plate #2, upper left, VF, stamps NH, margin LH. CV $350, (Image)

#C3 6¢ on 5¢ imprint plate block of six, plate #1, upper left, VF, NH. CV $300. (Image)