[A/S] Broken, open small vent next to rear fan, Argosy ''79

[ollphiast@xxxxxxx]

The Airstream folk have been been so helpful in the past I would like to ask 
another dumb question.
During a storm the top of a very small vent or small dome has been broken 
off.  A big branch must have hit it in a storm.  It is left, above the Argosy 
rear bath. It is to the left of the small fan vent, right above the loo, a 
sanitation vent?  It is nowhere in my Argosy Owners Manual 1979.
I am starting computer classes and do not want to fix it correctly, as usual. 
 If I cut a small rubber ball in half (hopefully cheerfully striped) and 
cheerfully glue it in three places to the top of the trailer, leaving a small 
space around the bottom, do you think it will be OK?  Or is this a vent that 
has to be completely closed?  I don't ever remember seeing it before. 
Is this something that can be repaired by a sloppy positive person? Or do I 
need a really money crunching repair person.  Isabelle