H4 Magneto Flooding problem

Make a long story short I bought a 49H about 2 years ago. She has been a great tractor and has never failed to start. Recently I moved her out of the shed to work on a different ‘H’. I only have room for one in the shed since the wind blew half my roof off. About a week ago the tractor wouldn’t start and I traced the problem to primary ignition. My first thought was a condenser or points. So I take the mag off and bring it in to the kitchen table. This didn’t make the wife happy but I have recently moved into a new house and haven’t built a good workbench yet. I had never rebuilt a mag so I start with changing the condenser, inspect and clean up the coil cover. Then I open up the points compartment and to my surprise water pours out. Everything inside was rusty.
I knew this wasn’t a good thing. I cleaned it all up with a point file and sand paper, new points, condenser, coil cover, cap, rotor and new gaskets. Well it worked GREAT, and I proceeded to use the tractor to cut about 25 acres over the weekend. Last week we get 3 inches of rain. I go out to start the tractor on Saturday and guess what. NO SPARKY. I take the coil cover off and it looks good. So I open up the point compartment and it is full of water and rusty again.

So the question is:
Is this flooding thing a common problem with H4 magnetos or do I have one that has a peculiar problem? I installed new gaskets and it still got soaked.
Also any suggestions on how to solve this problem?

Thanks
Ken B.