An authentic smooth dark brown example of this 1848 N-11 die state c  R6 die state with cud. The cud or Reverse Rim Break, RRB, is seen  boldly over ES on the reverse. The 1 cud example in RSB I, AU-50 1986, lot 1146, the Andrews/Starr lot realized $1,485 at the Chalkley sale in 1990. The 1 cud example in RSB III lot 535 EF-45, CC4 of 10 known sold for $517.50.  A chance to own this state residing in the NGC holder useful for grading and certification.   Only a very small group of N-11 coins would grade AU-58 in the NGC holder.A top expert indicates there are now 23 known of state c. This piece makes it 24 known.The expert also stated that the top coins for the state c are 55-50-50-45-45-40-40. If this piece is 45 it fits into center of that group.   Clearly a masterpiece for the variety and more so for the single reverse cud.