So I've made the decision to bite the bullet and remove the internal overflow, plug the holes in the back section and drill the back glass for a synergy shadow overflow and 2 returns.  
 
Needles to say I'm nervous about drilling 4 holes in a 3/4" starphire panel, but 6" of extra display room is to appealing not to try. I'm also hoping that the internal overflow is notched near the bottom inside joints, but I can't tell from looking so fingers crossed. 
		
	
		
		
		
		
			
		
		
		
		
	
		
		
	
	
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