In The Right Stuff (1983) lots of stock footage is used. There's one scene in particular that I'm pretty sure uses stock footage. But I'd like a confirmation. It's the scene when Alan Shepard is about to board the capsule and NASA engineers are watching him and clapping. Shepard looks up at the capsule and gives a thumbs up sign. Then he takes the elevator up and boards the craft. This capture is an example of what I think is stock footage.
The following is definitely not stock footage. It's a capture of the heavy handed character of the Minister, played by Royal Dano. The scene would have been much better served without these Dano inserts.