Ask someone at a museum?
			 
			 
			
		
		
		
			
			This is a long shot but may be worth a try.  
 
Query a museum known for its weapon collections.  
 
Also, consider quizzing the custodian of a library with an important holding of old/rare books.  
 
Old leather bookbindings sometimes can be restored by a careful stretching of the leather and possibly that technique could be used to restore your scabbard. 
 
The Imperial War Museum may have some kukris and know a thing or two about restoring and maintaining the sheaths.
		 
		
		
		
		
		
		
		
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