In the post about Kimball's designs I mention below, Amid Amidi mentions both the artists Art Stevens and John Dunn. Here is an excerpt of the interview with Art Stevens by Pete Docter that will appear in Walt's People - Volume 7 and that features those two artists:

[PD: According to his son, [Hal] King was hired from an insurance company, worked in the mail room, and then worked his way up from inbetweener. Does that fit with your understanding?

AS: I didn’t know that. In fact I’m the world’s worst about knowing any extracurricular activity and who socialized with who. Most of us were too busy doing our jobs. So long as I was able to turn John Dunn’s storyboards into living animation, that’s what made me happy.

PD: John Dunn was the story artist to end all, in your book?

AS: Yeah. He was. But only someone like Kimball would see his potential and adapt him to storyboarding. John was an individual that was not like any other person I have ever known.

PD: How so?

AS: He was unique. He had a terrible temper. And he would tell the most off-color jokes, they were almost embarrassing they were so off-color, but if I told one to him, he would be genuinely offended.

PD: One of his own jokes?]

AS: No, any dirty joke. He wouldn’t find it at all amusing. And nowadays I wonder why any of us thought any of them were amusing, but you were young then.