1967 Barracuda Fastback rear window

I'm not asking if you prefer "new" or why. I can tell you a used rear glass should clean up nicely. Those don't suffer from the elements like the front glass does. The reproduction rear glass that I removed from my notch had 2 flaws in shape near lower right corner that hurt overall appearance like 2 dents in the car. I did install a new front glass that I've had here for 12 to 14 years, it looks great. I installed a used OEM rear glass that looks great too.
Getting any quality reproduction parts today is a roll of the dice.
Good luck with your project.