Quote:
	
	
		| 
					Originally Posted by Rick
					
				 This piece appears to be of Sudanese origin . | 
	
 Rick you are right.
I finally found the picture I had in mind in Tirri's book "Islamic Weapons". page 75, figure 45.Title : A variety of Sudanese copies of Persian weapons.
For me that dagger is one of a set of 3 daggers disposed symmetrically in a sheath made of Crocodile skin. These weapons have been discussed in the forum following a photo send by Katana on july 26.2006.( I do not know how to stick a link here !) Other threads showing other examples of the same daggers can be found with a search : sudanese arm daggers. 
From these threads I conclude that this dagger may not be a cheap touristic piece but perhaps one of 3 daggers, normally sheathed  in a 3 blades sheath utilized for ceremonial or commercial deals in Sudan. 
Thank you Rick for giving the direction of search.
Michel