To fill in the small blemishes, use a Spot filler. It is made by Bondo, and can be found in the same isle of the auto parts store. No mixing is necessary, just quirt the filler out of the tube. Once the filler has dried, sand it smooth and add more as necessary. All of the red in the picture is the spot filler. If done correctly, you can primer the legs, paint, and they will look like smooth aluminum.