Thanks to all! 
Both blades are unquestionable wootz: very weak pattern seen. 
Yes, distilled. 
Yes, baking soda ( sodium bicarbonate) 
What %% nitric acid?  How long?  
  
 And, if the rest of the blade is still grey, any rubbing afterwards or some other method?
		 
		
		
		
		
		
		
		
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