Plate blocks of 6, #C20 with perf seps. Any faults such as thins, tears or pinholes that are not obvious from the picture are described above. Mint stamps have original gum unless otherwise stated. Find us on the web for a wide selection of other affordable stamps, covers and postcards.This item is in the category "Stamps\United States\Back of Book\Air Mail". The seller is "worldwidephilatelicsandcollectibles" and is located in this country: US. This item can be shipped worldwide.