Airmail, 1918, 16¢ green. Well centered, tied by Jul 15, 1918 Air Mail Service postmark on a legal-size cover to New York; some file folds, otherwise F.-V.F., scarce first day of the reduced 16¢ domestic airmail rate. Scott No. C2  Estimate $300 - 400. $0 (Image)

Airmail, 1918, 16¢ green. O.g., never hinged, beautifully centered amid large well balanced margins, rich vibrant color, bright and pristine, Extremely Fine and choice; with 2001 P.S.E. certificate. Scott No. C2  $140. $0 (Image)

Airmail, 1918, 16¢ green. Left margin single, o.g., never hinged, beautifully centered amid well balanced margins, deep rich color, very fresh, Extremely Fine and choice. Scott No. C2  $150. $0 (Image)

Airmail, 1918, 16¢ green. O.g., barest trace of hinge, deep rich color, Extremely Fine; with 2004 P.S.E. certificate. Scott No. C2  $75. $0 (Image)