Spread Bird Hallmark

by anna
(italy)

Hello I have bought a very nice vintage pin, it said to be sterling.

There's no "sterling" or 925 mark on it, but there's this bird you can see on the picture.
I've looked a lot of hallmark websites, there's the mexican eagle that is SIMILAR but not the same: first of all beacuse it seems to look left and not right.Then, it looks to have a "tail". I've seen a similar mark on a golden piece once, but I do not think this is gold..
Please give me your opinion, it would be precious!
Anna