Holes in my Head

[BobinSF]

New Year’s greetings to all afourians.
After patching a large hole in my head last spring, my raw-(salt) water cooled A4 is running fine, but with one problem: the head now has had numerous ‘pinholes’ develop. When I start the engine, after a few minutes, a very small trickle of cooling water will come out of these holes and make its way to the head depressions at the spark plugs, where it sizzles and boils. When this happens, I Dremel wire-brush clean and bright a nickel-sized area around the hole and apply three coats of JB Weld. This will usually stop that leak, but then another appears, and another, etc. My options seem to be:
1. I could just ignore this and run the engine with the sizzling and boiling, but that seems not a good thing to do, it being salt water.
2. Continue to observe new leaks and patch them as above, hoping eventually there will not be any new ones.
3. Replace the head, but seeing the accumulated rust on the stud and stud nuts (photo, before painting), this would seem very difficult or impossible.
4. Buy and install the MMI fresh-water cooled system (which of course I should have done years ago), and put one of the automotive stop leak solutions with the antifreeze into the cooling loop, after testing that the stop leak solution doesn’t degrade the impeller, and hoping that it stops the leaks.
Advice and opinions on this would be most welcome.