Maggi McNellis was the host of this 15-minute daily NBC program. It was broadcast from 12:30 to 12:45 p.m. from Radio City Music Hall in New York City. Stewart was on the show on January 23, 1947. The listing below is from the New York Times:
This show is not available, so the exact nature of the interview is not known. However, Stewart and Frank Capra had just appeared in Information Please the night before and were in New York to promote the opening of It’s a Wonderful Life, so it is likely that the film, and possibly Information Please, were included in the day’s discussion.
The atmosphere at the interview was quite relaxed as can be seen from the photo below showing McNellis and Stewart on the “set” of the radio show.
The following clippings is from the January 22, 1947, issue of Variety.
The radio interviews it is referring to are most likely this one and and a January 24th appearance with Martha Deane. There may also have been other, as yet undiscovered, interviews.