Hi Gord, also some of the naked edges are very tiny, those may be difficult to see when they are selected. There is a plug-in here that can help with that, it creates a point object at the start of selected curves:
http://moi3d.com/forum/index.php?webtag=MOI&msg=5288.21

But even after naked edges are patched up you still may have some problems if you try to do a boolean that cuts through an areas with little tiny microstructures in it.

- Michael