The for the ongoing ideas and suggestions. The vet I spoke with yesterday said he'll come by today to check out the bird. With any luck, he actually will.
I've found, as I wrote before, that most vet clinics here don't handle "street birds." What's more, as @jenndean said, La Protectora de Sarmiento doesn't help with birds. I just spoke with the owners and they said they don't have the room.
Will post a follow-up with, I hope, happy news.