I'm no expert on these cards but have had a few in the past and it looks like a good (and very nice) example of Musial.  The card stock is a bit more rigid than other sets from later on of both Topps and Bowman.  From the looks of the card as well as my personal ,yet limited, experience I think your cad is ligit.  Congrats! 
 
Drew
		 
		
		
		
		
		
		
		
		
	
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