I don't mean to pick nits, but if you are still tweaking it, the bottom of the plastron is a bit pointed for the 1st Empire period. It should be more rounded, as shown on this original: http://www.thierrydemaigret.com/html/fiche.jsp?id=1136557&np=18&lng=fr&npp=20&ordre=1&aff=1&r=
It's still a...