The Great Seal of the United States by U.S. Department of State, Bureau of Public Affairs contains details as to Pierre Eugene du Simitiere's role in designing the Great Seal of the United States
Finally they sought the help of a talented “drawer” and portrait artist, Pierre Eugene du Simitiere. To the post of consultant, Du Simitiere brought some knowledge of heraldry—the art of describing coats of arms—and also experience in designing seals.
The center of the original proposed design for the Great Seal of the United States by Pierre Eugene du Simitiere in 1776 appears to depict a heraldic shield which includes a Lion (heraldry), a Fleur-de-lis, and a Double-headed eagle, though this observation is not possible to verify based on the linked document, as there is no description within the document for the original proposed drawing.
Did Pierre Eugene du Simitiere specifically publish, leave in his notes and journals; or, do other primary source records exist of, a description the original proposed design of the Great Seal of the United States?