Good to know! My windshield may be original but it's at least as old as 1974 because it has an Ohio state inspection sticker from 74--the last year Ohio had state inspection.
(I lived in OH from 2001-2004 and saw a car go by so rusted out that you could see the window regulator through the hole in the driver's door!

)
Anyway, my windshield has upwards of 190,000 miles on it and the fine steel wool should be a big help for my windshield.