Originally Posted by
look566 rider
Get some auto paint polish or cleaner wax. Not wax, polish or cleaner wax. These have mild abrasives and will remove or reduce the blemish.
Take a bit and rub the mark, chances are it will rub off.
If he restores it pristine condition, he'll have to worry about getting the first scratch all over again. It's been my experience that people that people enjoy their bikes more when they stop worrying about them.
Or he can subscribe to eastern philosophy where a blemish is desirable because perfection is an insult to the gods.