I have a tiny amber thing which I think is of very similar construction - but not as sophisticated as this is. The foot is folded from the body, but there isn't a good seal - liquid gets into the foot.
I have never found out what it is, although I suspected it might be related to some recycled Mexican glass that was in a lot of gift shops and arcade stalls, some of which was kind of reproduction old that was around at the time I found it.
I don't think it's anything very good. For the last couple of decades, it's been sitting by my kitchen sink and I prop semi used brillo pads on it - they dry out rather than rust.
I am currently soaking it to clean it, to look for evidence of a cat's bum.