What county were they in? I have some Arkansas death indexes. If they are not in the index, it is unlikely that there is a death certificate.

I have the whole state for years 1941-1948

For years 1914-1940, I have the following counties in Southwest Arkansas.

Calhoun, Clark, Columbia, Dallas, Hempstead, Howard, Lafayette, Little River, Miller, Nevada, Ouachita, Pike, Sevier, and Union