VERY FINE. AN EXTREMELY RARE EXAMPLE OF THE 10-CENT LINDBERGH AIR POST ISSUE WITH THE TAB AT BOTTOM. VERY FEW ARE KNOWN.
There was strong public demand for the Lindbergh issue in booklet form, so the Post Office decided to issue this with six stamps per booklet. They were first placed on sale on May 26, 1928. The discovery of the inverted pane was first made in 1938, and fewer than a half-dozen others have since been discovered. According to a letter from the Bureau of Engraving and Printing (reproduced in the Bureau Specialist), they state that it is possible that the pane of inverted stamps may have originated from a sheet that became reversed during processing (cutting apart into the individual panes), and would have been assembled with the panes in reverse unless discovered before final assembly.
With 2001 P.S.E. certificate. We have offered only one other since keeping computerized records, from our 2010 sale of the Beutel collection. It was an exploded booklet
VERY FINE EXAMPLE OF THE GREAT SEAL EXPERIMENTAL DIE PROOF MOUNTED ON CARD. A UNIQUE ITEM AND AN ESSENTIAL PIECE FOR ANY AIR POST SPECIAL DELIVERY COLLECTOR.
Page 15 of The Airmail Special Delivery Stamps of the United States by Ralph L. Sloat states this die was originally meant for the U.S. Railroad Administration Pass Face 523. It was eventually used for the Air Post Special Delivery stamps. The Engraver Ponickau is also known for the 8c Trans-Mississippi and the frames of the Pan-American Issue among other designs.
With 2010 P.F. certificate
VERY FINE. AN EXTREMELY RARE LARGE DIE TRIAL COLOR PROOF OF THE 16-CENT AIR POST SPECIAL DELIVERY STAMP. ONE OF ONLY TWO EXAMPLES BELIEVED TO EXIST.
Undercatalogued in Scott. With 2010 P.F. certificate
VERY FINE. AN ENORMOUSLY RARE SMALL DIE PROOF OF THE 16-CENT AIR POST SPECIAL DELIVERY. ONE OF A FEW EXAMPLES BELIEVED TO EXIST.
With 1979 P.F. certificate
VERY FINE. A CHOICE EXAMPLE OF THE 16-CENT RED & BLUE AIR POST SPECIAL DELIVERY HORIZONTAL PAIR, IMPERFORATE VERTICALLY.
Datz states that only 10 pairs are recorded. With 1983 P.F. certificate
VERY FINE. THE UNIQUE CENTERLINE BLOCK OF FOUR OF THE 16-CENT RED & BLUE AIR POST SPECIAL DELIVERY, HORIZONTAL PAIR, IMPERFORATE VERTICALLY.
A single sheet of this error was discovered at a Buffalo N.Y. post office. It was ultimately broken up by H. E. Harris & Co. after showing the complete sheet at the 1947 New York City CIPEX Show. Datz states that 10 pairs are recorded. Very few blocks are known to exist including the unique plate block of six.
With 2001 P.S.E. certificate. Scott Retail as two normal pairs