Just to show those looking, here is some information & an example of the coin in question:
OBVERSE:
The obverse was designed by Melecio Figueroa and features a young Filipina in a flowing dress standing while striking an anvil with a hammer held in her right hand, her left arm is half raised and she holds an olive branch in her hand.
In the background is the Mayon volcano with a billowing smoke coming from the crater. On the upper periphery of the coin is the denomination "ONE PESO" and on the lower periphery is the word "FILIPINAS".
REVERSE:
The reverse design features an eagle perched atop a shield. On the outer periphery are the words "UNITED STATES OF AMERICA" and the year of issue.
To the left of the year may be a mint mark "S" for San Francisco. Coin with
no mint marks were minted at the Philadelphia Mint.
Variety 1: 1903-1906 - Silver Weight 0.780 ounces (26.956 grams @ 90% Au)
Variety 2: 1907-1912 - Silver Weight 0.514 ounces (20.000 grams @ 75% Au )
Years Minted: 1903-1912
Composition: 75% Silver (90% Silver 1903-1906)
Diameter: 36 mm
Weight: 20 grams (26.956 grams 1903-1906)
Total Mintage: 32,830,000
Mints: Philadelphia, San Francisco

The keys to the series are the 1906S and unobtainable 1907 proof issue (only 2 are known to exist).
Counterfeits of the 1906S are quite common so if you have the opportunity (and budget) be sure to purchase a certified coin from a reputable dealer.
The semi-key coins are the 1911S & 1912S issues.
For an undervalued coin look for 1904 issues, with a mintage of only 11,000 it represents a bargain when comparing value to mintage availability.
SMN: This site is showing the coin is 36mm, yet Wikipedia said it was 38mm?

(SAYS 36MM)
http://typesets.wikidot.com/philipp...so-1903-1912(SAYS 38MM)
https://en.wikipedia.org/wiki/Coins...lippine_peso