Images courtesy of WH

Significant examples:
Choice EF-45.  Ex - Stack's "The Marvin Taichert Collection of U.S. Type Coins", May 9, 2001, Lot 8, "Sheldon-18b", plated, sold for $14,950.00  Ex: Zabriskie Collection (Henry Chapman, June 1909, lot 734); Henry Miller Collection (Elder, April 1917, lot 655); Howard Newcomb Collection (Morgenthau, February 1945, lot 458); Dr. Sheldon; Homer K. Downing; 1952 ANA Sale (New Netherlands, lot 1636); Harold Bareford; Herman Halpern; Stack's sale of March 17, 1987, lot 107

Recent appearances:
PCGS VF-25 and Del Bland graded Very Good 8.  Ex - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "Benson Collection, Part I", February 16, 18-20, 2001, Lot 255, " 'Head of 1793', Sheldon-18B, Rarity-4, illustrated, sold for $3,680.00, Ex: Chris Victor-McCawley 2/87"

ANACS Fine-12.  Ex - Heritage Numismatic Auctions, Inc.'s "Long Beach Signature Sale", May 31-June 2, 2001, Lot 7483, "S-18b",  illustrated, sold for $1,552.50

VG-7.  Ex - Stack's "The University of Notre Dame Sale", March 20-21, 2001, Lot 75, "Sheldon-18b", sold for $1,150.00

G-4, Sharpness of F-12, heavily granular surfaces.  Ex - Bowers and Merena Galleries "The Rarities Sale, Orlando", January 8, 2002, Lot 80, "S-18b, Breen-2b, Rarity-4, Head of 1793," illustrated, sold for $460.00.  From the Dr. Roy Sturgeon

Net AG-3, sharpness of VG-10, heavy corrosion.  Ex - Bowers & Merena Galleries' "The Cabinet of Lucien M. LaRiviere, Part II", March 15-17, 2001, Lot 2415, "B-2b, head of 1793", sold for $414.00

Net Fair-2, sharpness of AG-3.  Ex - Bowers & Merena Galleries' "The Cabinet of Lucien M. LaRiviere, Part III", May 21, 2001, Lot 1332, "S-18b", not illustrated, not sold

Sources and/or recommended reading:
"Penny Whimsy" by Dr. William H. Sheldon

"Walter Breen's Complete Encyclopedia of U.S. and Colonial Coins" by Walter Breen

Relevant collector organizations:
Early American Coppers Club