Favorite Stove Works was in operation in Cincinnati from 1880 to 1888, after which it relocated to Piqua and was renamed Favorite Stove & Range Co. Value would be dependent on condition. Actually, it seems the most often marked items from the late 1800s are the tea kettles, e.g. there are no skillets marked Blacklock, but there are tea kettles, sad irons, etc. that are.