Many French makers used the same scrolls as there was a carvers guild that made them. The makers we not allowed to make the heads as there were guilds in place for carving and finishing. I have seen that Scroll and gears like that on many different brands of basses. They would usually buy the scroll/neck and put it in the instrument. Mass production in France from the late 1800s thru the early 20th century. This is what I have learned.
Andre Morel is listed in the books. Possibly like other makers, they would add their wife's name to the business. Maybe for Taxes. Jacquet-Pilliment and Jacquet-Gand for instance.
I just sold a bass by Paul Manegot, attributed to him based on another exact bass that was labeled. Similar model but the head was closed.
http://www.kensmithbasses.com/double...not/index.html