It is a rostrato piece. Rostrato was done by Ferro, Toso, & Barovier in the late 1930s, but was copied by others. You might be able to attribute this with a good bit of certainty if you check for Barovier chandeliers. Much luck! Rostrato fetches a good price if it is original and if it sells. Many people shy away from the form -- why, I don't know.