5c Blue, perforated 12 x 10 (428a), used vertical pair, both stamps the error, fresh bright color on bright crisp paper, bottom stamp has a single rounded corner perforation,

5c Blue, perforated 12 x 10 (428a), used vertical pair, both stamps the error, fresh bright color on bright crisp paper, bottom stamp has a single rounded corner perforation,

OTHERWISE FINE, AN EXTREMELY RARE ERROR OF PERFORATION, A WORTHY ADDITION TO ANY SPECIALIZED WASHINGTON-FRANKLIN COLLECTION, Scott retail $4,500.00