How to restore the black plastic on my turn signal?

Any ideas how to restore this plastic?https://imgur.com/a/oZhwAUZI've tried the restoration stuff used on car plastics but it did nothing. It seems like the finish is actually taken off. via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/9e4idd/how_to_restore_the_black_plastic_on_my_turn_signal/?utm_source=ifttt