I can confirm that the librarian giving direction is Elvin E. Strowd, then Circulation Department Head, for many years my manager, mentor, and friend: A truly remarkable man with an abiding interest in his many student assistants.

The librarian with the clip board appears to be Dr. Benjamin E. Powell's and John P. Waggoner's secretary, executive administrative assistant in more contemporary parlance. To her left is me.

At this location, a photo - https://www.flickr.com/photos/dukeyearlook/13904580002/in/set-72157621179687840 . The stern expressions of Mr. Strowd and Mr. Wagner are not characteristic; must have been influenced by bright sun light. Elvin and Jake consistently presented friendly, welcoming persona.