Is there a way to figure out which country an iPhone came from or which country it was originally intended to be used in? I have an iPhone 3GS, which isn't activated and is stuck on the emergency screen. I put in multiple AT&T sim cards which always allow me to activate an iPhone. But for this specific iPhone 3GS, iTunes says the SIM cards are invalid.

I am guessing this iPhone 3GS came from outside the USA. Is there anyway I can figure out where it came from?