This stamp, known as "Position 58," was valued at between 
$525,000 and $1.6 million.

(AP) – An ultra-rare stamp could sell for more than $1 million when it hits
the auction block in New York City next week, analysts have estimated.

It was one of 100 "inverted Jenny" stamps, legends among collectors. They
were issued in 1918 to celebrate the launch of U.S. air mail, but showed the
Curtiss JN-4H "Jenny" biplane inverted. A smart customer bought a 100-
stamp sheet before anyone realized the error.

According to the auction house, the stamp hitting the auction block on May
31 was “remarkable for its pristine state of preservation and for its centering”.