Radiator Overflow

[LynnC7738@aol.com]

Several years ago, on my Series I, my mechanic( engine rebuilder) fitted an 
overflow container to my radiator. The engine was overheating at the time.  
It's mounted on the firewall on the right side. Now I want to add an original 
windshield washer ,  and of course the bottle mounts on the right side where 
the overflow container is. The question is , what happened to the overflow, 
if any, in the original cars? 

Lynn
Series I Alpine