Hi Jim, I haven't taken a look at your specific object yet (I will in a minute), but there is a tutorial on object repair techniques available here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

That covers the basic techniques which involve separating out surfaces and doing an "untrim" to erase trim curves off of some surfaces to recover the full underlying surface that is underneath a trimmed surface.

- Michael