sure would help if you could figure out what the lettering to the top and right of the portrait (obverse) said. Maybe do a pencil rubbing to see if you can get the lettering.
Here's a website that gives a picture of an 1860 10 centime from Cambodia http://art-hanoi.com/collection/iccoins/cbkm43.html From your picture, I can't tell which year it is, it could be any between 1860-1899, I guess.
According to Yeoman's Catalog of Modern World Coins, that particular piece was only minted in 1860. On edit: Apparently this was a one-year issue, perhaps to mark the ascension of King Norodom 1. A few years later, coins for French Indochina were issued which were used in Cambodia, Laos and Vietnam.
Got it. Even though it's almost completely worn, It it going into my collection until I find a better one. Thanks to all that replied.