Well, I am no leather wizard, so excuse the idea if it's stoopid.......How about a little thinner strips of leather with a layer of kydex in the middle?  That way you could end the kydex before the end that doesn't want to fit through the buckle. 
 
 
 
 
Yes, I spelled "stupid" wrong.......it's a JOKE!
		 
		
		
		
		
		
		
		
		
	
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