At the bottom of this page you'll find similar (but not an ebony model) with the names Cognet company uses for them.
Couteaux fermants Le Thiers© Conçu suivant la charte de la Confrérie du Couteau de Thiers, le Thiers par P. Cognet est réalisé au sein de la Manufacture.
www.coutellerie-cognet.com
Your knife is very nice, a Douk Douk it is not.
I'm going to back pedal a tiny bit & say a
traditional Douk Douk it is not. I imagine since the dirt cheap Douk has gained so much web popularity over recent years Cognet is using it to draw attention to other models.