Given the fact that these cars are 30+ years old, and a windshield is in the top 10 list of things that just might not be there 30 years later, I dont know just if how much a original dated 'shield would add to a car. But what do I know.
Buffing windshields, I do know that tho. It is possible to buff lite scratches from windshields. You make a paste with cerium oxide(its very, very messy)and use a felt wheel to buff with. The big draw back is that you can distort the windshield ie: buff depressions into it.
I have been told that all these new date coded 'shield are just that. They have buffed away the date if not the complete label, left a depression, and etched a new date into it.
If you were to hold a new 'shield up to the lite and look at it like you would your paint down the side, and use the bulb to scan the glass, any flaw will stick out be it a 'seed'(and no, not that type, you find those in the upholstery
)a scratch or where somebody has tried to buff a scratch out. A word to the wise tho, your wasteing your time trying to buff tempered glass, its to hard(the glass is).
Fixing chips, depending on what type it is, piece of cake. And if you get somebody that will take his time, almost non detectable.
67 Camaro SS Conv.
70 Challenger R/T Conv.