Both Peter Marshall and CNR had major parts in a short-run 1965 musical, Skyscraper. https://www.ibdb.com/broadway-production/skyscraper-3264#OpeningNightCast
I did not realize that! I know of Skyscraper for its OTHER game show connection, though: Dorothy Kilgallen attended a preview and reviewed it, which was very much against the norm. People were very upset.
Steven Suskin's
Second Act Trouble reprints a piece by Jack Gaver that includes both the relevant comments by Kilgallen on
Skyscraper and offers commentary on the situation- it makes for an interesting read (particularly with Suskin's own comments explaining the context in which the Kilgallen issues occurred).