Hello Fernando,
I am not sure as well, I've seen a few in the same style like the one in question, all with the same parameters and I've noticed that there are a lot of similarity with the so called (frensh) dagues de pute, mainly the scabbard style so I think that they are from the same time frame and maybe the same workshop. I think that we only can guess if this daggers with curved blade are dagues de pute or coupe de grace like the german nickers. The reason why I ask in my initial post.
Regards,
Detlef