What is that slow, dreamy music they play only on the lost episodes, when Ralph is regretful or sad about something. For instance, at the end of the Adoption episode, when they have to give the baby back, it's the music playing in the background. Where can I get this music as heard in the show?

The song used most often under Ralph's apologies/sadness at the end of the episodes was "Our Love Is Here To Stay". Not sure if that was the one used in "The Adoption" show, I'll have to check it when I get a chance. In the classic 39 and the final live season, a slow version of the Honeymooners theme ("You're My Greatest Love") was generally used.

The "Lost Episodes" featured the episode intro to Irving Berlin's "I'll Be Loving You Always".