Lot
1410 
1917, 11¢ light green, perf 10 at bottom, block of 4, lower right perf 10 at bottom, lower left transitional perf 10, o.g., never hinged, bright color, fresh & Very Fine; with 2000, 2007, and 2014 P.S.E. certificates.Scott No. 511a $12,000.
AN EXTREMELY RARE AND SPECTACULAR ERROR BLOCK.