David Akers (1975/88): The 1854-S is one of the more common dates of the No Motto type, at least in low grade, and is the most common S-Mint Eagle prior to 1879. However, in AU condition it is rare and in uncirculated it is very rare. The superb piece in Paramount's 1973 Grand Central Sale is the finest I have seen but I have also seen two other very choice uncirculated examples. Since a Double Eagle of this date was struck in proof (it is in the Smithsonian Institution) it is possible that a proof 1854-S Eagle was also struck to commemorate the opening of the San Francisco Mint. This is strictly conjecture, however, and no such proof is presently known or even rumored to exist.
Ron Guth: A curious aspect of the Eagles produced at the San Francisco Mint is the placement of the mintmark. On the majority of Liberty Head Eagles, the mintmark was placed on the reverse just below and between the talon and the fletch of the arrow (for example, check out any O-Mint Eagle). However, San Francisco became an exception right from the start, when it placed the mintmark on the 1854-S Eagle further to the right, just below and between the fletch and stem end. This is true on virtually all of the No Motto $10 Liberties, though one 1856-S variety is an exception and shows the "normal" placement of the mintmark. Beginning in 1866, the "S" mintmark becomes very small and is placed in the "normal" position, as well.