Ron Guth: In 1905, the Philadelphia Mint struck 471 Proof One Peso coins for the U.S. Philippines. Because the Philippines were a U.S. Territory at the time, these coins are truly dual-country coins -- one side clearly states UNITED STATES OF AMERICA and the other reads FILIPINAS. As such, they are immensely popular with collectors because of their loow mintage, their appeal to collectors of both US and Philippines coins, and their simplistic beauty.
High grade examples of the Proof 1905 1 Peso are quite elusive. Many examples have been protected carelessly over the years, and the typical example shows hairlines or other evidence of cleaning. At the top end, the PCGS CoinFacts Condition Census recognizes ten examples ranging in grade from PR66 to PR67, the finest being three at the PR67 level.