Don't bother trying to clean up your old clamp, just buy a new one!
It will look better and save you time messing around, when you could be doing something more worthwhile, like checking our online product gallery and schematic for your model, and seeing other items that you may need to order but overlooked.
The more comprehensive your order, the better value for you in reduced shipping costs, when divided over the number and value of your order. Whatever type of Japanese bike you own, check out the products gallery and online schematic for your model, and keep it, at all costs, looking pretty!