Intricately carved framed mirror

This ornate mirror caught my eye at an estate sale. It is 44" wide by 36" high. The owner only told me it had hung in his father's antique store for many years. From the layers of dust on it, I could well believe it. It is quite heavy, but I can't tell if that is due to the thickness of the mirror or the type of wood it is made from. I am guessing that it is from the late 1800's perhaps, and what I think is the American Barbizon style. Maybe someone here can correct me if I'm wrong. It has flaking of whatever was used to cover the sides (looks like plaster over wood and then the paint?) but I only paid $40.00 for it and absolutely love it, so consider it was a steal. :)