You may find the grips are numbered----in pencil-----and virtually invisible after the passage of a loooooooooong time.
Oft times you will find there's no remedy, but just as often you'll find the combination of STRONG, high intensity light and viewing from an angle makes for a remedy---and BEHOLD!!--------they're numbered after all!
Ralph Tremaine
As a belated aside, rumor has it taking a (flash) photograph taken from an angle will show you what you couldn't see with just your eyes. I've never done this, but I've seen the pictures of the numbers.