galloping horse windvane

This galloping horse windvane came to me by way of my grandmother who purchased it at a yard sale. I know nothing about it and can't seem to find any definate information on it as i've realized that researching it is very difficult. It has no marks on it that I can find. The horse is 32" from front hoof to tail and 17" from tip of ear to front hoof. I believe that it is copper and it has the blue/green petina. The head however is very heavy; cast iron maybe? Any information would be greatly appreciated. I've just been informed that the head of this horse is brass.