There were all sorts of things were recorded to film (or transcription audio records) for members of the US military who were stationed abroad. A little bit of home.
I’ve seen lost episodes of the Tonight Show turn up this way as well (from the 1960s).
The Tonight Show epis I'd dearly like to see (NBC recorded over them...), or at least listen to, are the ones of Bill Dana's "Jose Jimenez" appearances during the Apollo 11 mission.