Any tricks to get haze off windshield?

I was trying to find my buddy a good used windshield for his '54 Belair becuase it's got an unknown haze on it and will not come off. We've tried everything we can think of- vinegar, headlight cleaner, sanded it with fine sandpaper nothing helps. It is definatly on the outside of the gl***. It helps to wet it down to see temporarily. Any ideas you guys know of would be great becuase a new windshield is $400-$500!!

 

Bon Ami or Bar Keeper's Friend usually cuts most haze for me.

 

bar keepers friend, my dad swares by the **** for almost anything. its worth a shot

 

a razor blade, laquer thinner and steel whool usually do the trick. not in the that order but it usually works.