Quoted from MikeS:
I think it's just my pinball OCD kicking in since I tend to always put brand new glass in my other pins whenever I encounter scratches.
Give it about 5 years.... Your kids will fix your OCD for you..... The glass will be the least of your concerns once you see all of the cool artwork they draw on the sides of your machines to help you out...
You could try a kit out like this-
amazon.com link »