unmounted mint Block Larger Than four 6c Dark Blue & Carmine imperforate vertically (C23b), the unique top arrow, double 'Top' and double plate no. block of six (with the registration marker at top left) contained within a top margin block of ten, full original gum which is never hinged, usual natural gum creases (one is a trifle heavy),

SIX CENTS DARK BLUE AND CARMINE IMPERFORATE VERTICALLY THE UNIQUE PLATE NO. BLOCK OF SIX

Details

unmounted mint Block Larger Than four 6c Dark Blue & Carmine imperforate vertically (C23b), the unique top arrow, double 'Top' and double plate no. block of six (with the registration marker at top left) contained within a top margin block of ten, full original gum which is never hinged, usual natural gum creases (one is a trifle heavy),

EXTREMELY FINE, AN EXTRAORDINARILY RARE UNITED STATES AIR POST MAJOR ERROR, UNIQUE AS A PLATE NO. BLOCK, Datz and Scott retail for two error pairs is $20,000.00, the plate no. block is unlisted, Datz states that only five pairs are known

Lot Essay

Note: only one sheet of 50 existed partially perforated diagonally instead of vertically, this unique sheet produced this plate no. block of six and only three other horizontal pairs imperforate vertically. Most certainly a major United States error of the first magnitude which is lacking in nearly every major specialized United States error and Air Post collections. est.