it is possible to polish scratches out of glass. there are a few companies, Eastwood I believe is one of them, that carry kits for polishing windshields on antique cars. in order to replace the windshield on a 1948 packard is not only expensive, but also degrades the value if the original glass is not used, it is highly sought after. if you can polish glass scratches out, you might want to talk to a few restoration shops in your area. lots of guys want it done, but don't want to pay the initial investment for something they are just going to use once, maybe twice. it's not cheap to do once, but if you can polish enough glass with it, it's worth the time.glass is harder than acrylic, to this day I haven't heard of it being possible but my ears arent that open, but i wish you luck, if i were you i would diy it =]