You might check with
Safelite Glass if you have one close to you. They're a nationwide chain. Before I painted my 63 I was thinking of taking the windshield out to put in new rubber. Around the same time I had a windshield crack on my DD truck. Safelite came out and installed the new one and while the guy was here I showed him my 63 and asked him if they did these. He said they did, same price as newer cars ($125) if I supplied the rubber. One hitch was that if it wasn't a new glass bought from them, there was no guarantee it wouldn't break. That's why I didn't do it. But, this guy had done plenty of old vehicles and said it would most likely be no problem.