3c Blue Green, Special
Printing (169). Without gum as issued, huge margins, full and intact
perforations at top and right, scissors-separation at left and bottom,
fresh and bright colorVERY FINE AND CHOICE. LESS THAN 40 3-CENT CONTINENTAL HARD-PAPER SPECIAL PRINTINGS ARE BELIEVED TO EXIST.
The Scott catalogue notes that "Although perforated, these stamps were usually cut apart with scissors. As a result, the perforations are often much mutilated and the design is frequently damaged." For additional information, please see an article by William E. Mooz in Chronicle 183 titled "Scissors Cutting of the 1875 Special Printing Issues." The example offered here, with its design complete and perforations intact on two sides, is among the finer examples known of this rarity.
With 1967 P.F. certificate (Image)
24c Dull Purple, Special
Printing (175). Without gum as issued, scissors-separated as usual
leaving intact perfs on two sides and many perfs on a third, rich color,
fresh and Very Fine, approximately 80-90 are believed to exist, with 1987
P.F. certificate (Image) 
30c Greenish Black, Special
Printing (176). Without gum as issued, beautiful bright shade,
well-centered with wide margins all around, scissors-separated as almost
always but leaving virtually intact perforations at top and left and many
perforations at rightEXTREMELY FINE AND CHOICE. A SUPERB EXAMPLE OF THE 30-CENT CONTINENTAL HARD PAPER SPECIAL PRINTING. AMONG THE FINEST OF THE APPROXIMATELY 40 EXAMPLES THAT ARE BELIEVED TO EXIST.
With 1988 and 1996 P.F. certificates (Image)
90c Violet Carmine, Special
Printing (177). Without gum as issued, intense shade on bright fresh
paper, scissors-separated as usual but leaving many perforations full and
intactVERY FINE AND CHOICE EXAMPLE OF THE RARE 90-CENT CONTINENTAL HARD-PAPER SPECIAL PRINTING. ONLY APPROXIMATELY 40 ARE BELIEVED TO EXIST.
With 1952 P.F. certificate (Image)