Breen (1989) cited Proof examples for JR-2 and JR-4. However, Davis et al (1984) could only confirm the existence of a single Proof 1825 Half Dime, that being the Bareford (Stack's 10/1981) sale. Both the Norweb and Pittman coins came on the market after Davis et al published their book, as did two other pieces.
Today, there are five Proof examples known of the JR-2 variety and a single purported Proof of the JR-1 variety.
Sources and/or recommended reading:
"Walter Breen's Encyclopedia of United States and Colonial Proof Coins 1722-1989, New Revised and Corrected Edition" by Walter Breen (1989).
"Early United States Dimes 1796-1837" by David Davis, Russell J. Logan, Allen F. Lovejoy, John W. McCloskey and William L. Subjack (1984)