FWIW, I had a couple 80s cards in screwdown holders that have been that way since the 1980s, and last year one came back a PSA 10 and the other a 9.  So, the screwdown does not necessarily alter the card corners.  I guess you won't know until cards are submitted, but just figured I would mention it.
		 
		
		
		
		
		
		
		
		
	
	 |