I have just found on the web an article featuring many references on Billaud's scary wig and other information. If you are interested in, check it here: http://www.andreversailleediteur.com/?bibv=109. Of the same author (Lenotre) there you'll find different rev-related articles too, such as "Saint-Just en Blérancourt", "Mademoiselle Robespierre" and many other else !