Was the school Arizona School for the Deaf and Blind? I'd love to obtain some family-album-type photos! I have one low-quality photo of Hilbert and LeRoy, obtained from Gallaudet University Archives, and taken from a printed newspaper or magazine (so it shows obtrusive dots). That may be the only photo of the Dunings in their files. I know that the "Silent Worker" (later renamed "Deaf American") published an article about the brothers' architectural firm, designs, and buildings; I have a photocopy of that. Most of the "Silent Worker's" photos are, as best I can tell, in the Gallaudet University Archives; I haven't been able to obtain photos from the NAD in many a year.
Do you know about the Babbidge Report? Your grandfather was one of two deaf members of the Congressional committee investigating education of the deaf. the report was issued in 1965.
To get an idea of what DEAF LIFE's "Deaf People in History" installments look like, here's a link to an interactive sample copy: