This was the only use of the obverse and reverse dies. 1819 Newcomb 2 is another, slightly different overdate, but it is better known as the 1819 Large Date variety.
Regarding Proofs of the 1819 Newcomb 1, Wright noted in 1992: "One Proof example is known to me - the Beckwith:54 - DuPont:568 - Pittman coin. The Mougey:121 - Sleicher:1043 piece, purported to be a Proof, is currently untraced. It is definitely not the Beckwith coin".
In the Pittman sale catalogue (1997), Akers speculated: "The Mougey coin may or may not be a different specimen from the DuPont coin offered here".
Breen noted in 1988: "At least 2 proofs reported." Apparently, he was referring to the Pittman and the Mougey coins.
The Pittman coin (ex - Beckwith, Lot 54 - Stack's "Anderson-Dupont" 9/1954:568, $70.00 - John Jay Pittman - David Akers 10/1997:196, $19,800 was subsequently graded MS62BN by PCGS (cert #4837984). Later, the coin appeared as an NGC PR64BN in an advertisement in the April 7, 2003 issue of COIN WORLD, where it was offered by North American Certified Trading for $34,000.00. In the opinion of several experts who examined this coin at the 2005 F.U.N. show, it is not a Proof. Also, plate-matching indicates that this is not the Beckwith coin.
Sources and/or recommended reading:
"The Cent Book 1816-1839" by John D. Wright
"Walter Breen's Complete Encyclopedia Of U.S. And Colonial Coins" by Walter Breen