I saw Gantry on the last night which alas, was also the opening. We were in the front mezz and could see that Shaw had script pages taped into an open bible that the character carried for several scenes.
The score had some lovely songs. Some of them were reused later in a musical television version of The Gift of the Magi (Was it with John Rubenstein?) which I did not see. The music was written by Stanley Lebowsky who was one of the top Broadway conductors before and after. Gantry was his only show.
Elmer Gantry did become a second musical (same source, different authors) later in the 70s also called Gantry. It played Ford's in DC to good business, and the reviews were okay. There was some interest in bringing it in. That didn't happen.
Ted Thurston was a friend of mine and he was so good.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher