Indeed, hammered copper range hoods, tabletops and bathtubs as well as sinks can be hand polished. Since copper they are made of is fired it will show some color variations even after polishing it. The color is similar to brand new US penny, perhaps little bid more shining. Usually, there is some extra cost associated with having the range hood or tub polished as it is labor extensive. It might take a week to have an average size range hood or bathtub hammered copper polished.
Polished Copper Tubs and Range Hoods