I was thinking about the horse head and thought I would put an idea out there. Do you think the first line might be Ermanno, with what looks like a G actually being a distorted E? If it is Ermanno, there is only one person I can think of who would have made the horse -- Ermanno Nason. His work is signed in different ways from the little I've seen. If I remember correctly, some of his things are signed Ermanno, other things E. Nason, and still others with his full name. Unfortunately, I don't have any pictures of the signatures.
I am probably reaching, but thought I would mention it as a maybe. He designed and made a lot of horses in his long career. Your horse would fit in with the type of work he did in his later career.