Early Taxco, or Pre-Columbian Re-do?

I'm a fool for early (pre-eagle) Taxco sterling, and this guy was unusual in that he is smiling. In Taxco "green onyx" (glass, actually) masks, it's pretty much the same face, over and over again—a grumpy-Muppet-looking dude with his eyes shut and mouth firmly DOWN. But here we see him smiling, mouth open. I've never seen another like him. And look closely at his back. It looks worn, much handled, and there is a chip where, logically, there oughtn't be, protected as that spot is by the hardware.
I put this piece under the needle of my Presidium 2 tester and it comes up everywhere from quartz to nephrite, depending on where I slide the testing needle, which suggests that this stone was quarried, and moreover from a quarry that was tapping out of money-stone, nephrite jade. I don't know; I just have a strong, gut feeling this was an artifact that some enterprising soul crudely wired into a brooch for fast tourist moola, when Spratling's stuff went radioactively hot and Taxco silver was selling like chupas. But I'm willing to have my fantasy punctured, so have at it.
Oh, I forgot to mention that he was minus his earrings when he came to me. I made replacements. (I am a jeweler.)