A truly amazing hybrid Miguel, thank you for bringing it in here! 
 
It has been a long time since we have discussed these Dahomean hwi it seems, and for those interested in further reading on them, Christopher Spring in "African Arms and Armour" has a good section about them.  
He uses plates and data from "Sabres Decores du Dahomey" 
                                            Montserrat Palau Marti 
                                            Objets et Mondes, VII:4, 1967 
These fascinating ceremonial blades on these hwi reflect the tribal animist traditions and often facets of the West African Vodun religion.  
 
This does appear to be a French briquette sword as noted by Kubur, and these were around latter 18th century, well into the 19th. They were replaced my a gladius type sword M1831 but both seem concurrent in 1830s.  
The hilt on this one seems likely 2nd Empire c.1854+   
While the French did not colonize Dahomey until 1872, I have researched hwi which were collected there c 1856 by French officers.  
 
Fascinating example reflecting the Dahoman traditions coupled with French colonial situations, and great historical possibilities,
		 
		
		
		
		
		
		
		
	 |