Where can I buy new glass for my '63 convertible?

Have you tried ECS Automotive Concepts? The carry some date coded glass. Not sure about glass for a '63 model. It's all flat glass except the windshield, so, it shouldn't be too hard to cut some glass and temper it. Might be expensive though. The glass should be the same from '63-6 for most of it. The vent glass is hardtop and convertible only, the door glass is also convertible and hardtop only except Barracuda. and the quarter glass is convertible only. Naturally, if you go used or new ones off the shelf, there will be differences in date codes and logos.