Also-J.Lynch, Am.Heros MS66-
Jaime Hernandez: The 2004-P Jefferson Nickel received a new reverse design this year. From 1938 - 2003 the Jefferson Nickel carried the same basic Thomas Jefferson obverse along with the Monticello Building reverse.
In 2004 the obverse remained the same and the reverse was changed to a Peace Medal design. The 2004-P Peace Medal design is a one year type as the reverse was changed again during the year, but this time to a Keel Boat design. Both the Pace Medal and Keel Boat reverse designs were only used in 2004.