CR55
It's just a little surface rust!
Listen to rodguy1 and Darkk, 2 excellent choices. I had a glass guy come to my garage and cut glass. Very easy once you know the technique!. Curved glass is another ballgame! But it can be done. I don't think the sanding routine is an option due to the fact like Rodguy said...Breaking it on the last couple of inches! Too much labor involved. Find a competent glass shop and let them cut it for you, saves a lot of aggravation!..Good luck with the project...CR