iirc carbon dating wouldn’t really work since that’s for organic material specifically. But instead of the age of the statue being the main point of concern, I can do you one better. If you make it out of some kind of alloy that doesn’t occur in nature, it would further indicate that something has far more advanced knowledge than the era would ever permit. Also, I’m pretty sure that because of nuclear testing putting specific elements into the atmosphere, a lot of materials carry some form of these trace elements, which would indicate knowledge of atomic weapons! (though idk if this would still be a thing or not after thousands of years of the statue being exposed to the elements)