vintage silver deer pin handcrafted metal art Mexico sterling silver?

Tarnished silver deer pin (actual pin of this brooch is steel, has a little rust). The deer is stamped something on the back - I'm almost positive one word here is Mexico, and I just can't make out the rest of it, sorry.

Maybe it's sterling, I don't know. I saw a few of this type of deer pin shown online called sterling, but I don't have a kit to test it, so who knows. It's too cute to scrap anyway, right? Tell me you won't scrap this little dear (pun intended)!