Have Gun Will Travel was the only TV show made into a radio show during the golden years. Gene Roddenberry wrote the scripts of many of the early shows.
I don't want to be a downer here, but I bought the DVD box of the first season, and I was sadly disappointed.
The TV show's first year was I think 1957-58. The next year, they started the radio show, using the scripts of the TV show's first season. Not so great.
However, the following year, the radio show used its own scripts (many by the great Anne Dowd [sp?]). They were terrific! The second year of Have Gun is my favorite radio show. The radio show was directed by the guy who directed the Gunsmoke radio show (Norman MacDonald?). Everyone with Gunsmoke was disappointed that they were not allowed to be a part of the TV show. So the radio show director took special delight in proving that he could do Have Gun better than the TV show guys could.