With all due respect I may add a different perspective to the etching question.  I would look very closely at the blade to see if any pattern is there.  Perhaps you could etch a small section, a "window" as they say in the Nihonto collecting terms.  If there is a pattern, I would etch it.  If not, don't bother with the rest of it.
		 
		
		
		
		
		
		
		
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