Aide-mémoire à l'usage des officiers d'artillerie de France attachés au service de terre..... 2 vols. 1809:
Index page re pontoons: http://gallica.bnf.fr/ark:/12148/bpt6k63667990/f65.image
Pontons start on p. 54: http://gallica.bnf.fr/ark:/12148/bpt6k63667990/f137.image and continues through ca. p. 79. You will see quite a variety of waterborne craft used by the French pontoniers.
Indeed light copper or iron sheathed pontoons were used as well as both old and new model wooden pontoons. An Austrian style pontoon was also introduced. One pontoon per carriage was the norm in France.
Metal scheathed ponton and carriage: