The following is a research note I found while hunting down Sompayrac in Louisiana:
The Manuscripts Department of Tulane University has significant holdings pertaining to art, artists, and art organizations in New Orleans and Louisiana. source:http://www.tulane.edu/~lmiller/Artists.htmlhttp://www.tulane.edu/~lmiller/Artists.html
One such title:
Sompayrac, Willard, Irma, Papers 1933-1963, 9 pieces, Manuscripts Collection 671. Includes a scrapbook of articles by Willard, the draft of an article on Louisiana history, two papers on the origins of the natchitoches Art Colony, and a copy of the Report on Art Archives written by Willard as State Supervisor, Art Education Department. Also includes a genealogy of the Sompayrac family.
Hope this helps someone.Maybe someone in Louisiana could check on this and relate any genealogical gleanings that are found.