Series: Patterns - MS
Judd 9, Judd 10 and Judd 11 are from the same pair of dies. Judd 10 has a reeded edge; Judd 11 has a plain edge. The presumed emission sequence is Judd 11 first, then Judd 10, followed by Judd 9.
Sources and/or recommended reading: "United States Pattern Coins, Experimental and Trial Pieces", Eighth edition by J. Hewitt Judd, M.D.
"Walter Breen's Complete Encyclopedia of United States and Colonial Coins" by Walter Breen