Post Office Dept., 1873, 6¢ Post Office Lincoln Essay, Die in Black on White Ivory Paper, 63x71mm, essay features an incomplete engraving of the Lincoln vignette without rectangular frame design, Very Fine, ex-Ainsworth; with 2009 P.F. certificate. Scott No. O50-E1  $4,250. A HIGHLY IMPORTANT AND RARE ESSAY FOR THE OFFICIAL OR LINCOLN RELATED SPECIALIST, ONE OF THE FINEST OF ONLY FIVE RECORDED. This frame was apparently in progress when the decision was made to switch the Post Office Department design from the portrait vignettes to large numerals. $0 (Image)