Well, how bad are these scuffs? Plus, is your helmet painted in enamel or acrylic?
What helped me fix a scuff mark on my enamel painted helmet was dabbing a VERY small amount of paint on a cloth, and rub it on another piece of cloth until the paint is virtually dry, but there's enough to rub onto a surface. In small circles, rub the scuff with the cloth until you get it concealed. Wait for it to dry, and then very lightly,buff it with a #0000 wool wire to smoot the surface. Repeat if necessary.
Hope this helps you out man.