Yup, that buttplate is pictured in Houchins and I have an early Fulton gun with one identical to it. They are scarce, but certainly factory. I have only seen one mint example, own it, and would be willing to allow it to be duplicated if someone knows how to make a mold without disturbing the original. A friend has some molds but I don't think he made them, so I wouldn't know where to go. It is a beautiful buttplate when in good condition.