They are sometimes very tough/impossible to restore completely... usually the dents along the outside edge are totally un-removable. These caps are very easy to find, but very difficult to find in perfect condition. Almost every one of them that is not NOS will have some sort of gouge or dent in them somewhere... I have already sorted through stacks of 25-40 caps and not found a single dent-free one. It seems like everyone must have removed these from the wheel with a pick axe or an air chisel.
