I think the "coin" is dated " .368", if my eyes  are still what they used to be ???? years ago:-) 
 
 If so, - 1948-1949. I think it fits well with the crispiness  of incisions on the blade. 
 
 But Jim is correct: the "coin" could have been attached to older knife or might be older than the knife itself.
		 
		
		
		
		
		
		
		
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