Lot
1497 
1894, 6¢ dull brown, imperf horizontally, bottom margin plate no. "28" block of 6 with imprint, o.g., fairly light hinging, rich vibrant color, some expertly reinforced perfs and top right stamp with small thin and light crease along top edge, Fine appearance; with 2013 P.S.E. certificate. Scott No. 256a $30,000.
THE UNIQUE BOTTOM MARGIN PLATE BLOCK OF THE 1894 6¢ BUREAU IMPERFORATE HORIZONTALLY - A GREAT BUREAU ISSUE RARITY.
Only two plate blocks are known of this error. The other is plate block of 9 (ex-Col. Green) from the top of plate 28.