If, you can feel the scratches with your fingernail, they won't be eliminated, but they may be able to be reduced slightly. Over all it should do well at improving your over all visibility.

Also check around with most automotive glass shops (more than just the quick fix chip repair places) as most will be able to get you a new windshield for a pretty good price. Usually under $200-$250 installed and if they are a good shop, many will have at least one tech that has done older cars. You want to have them take extra care with your trim!

Brett!