You can't automatically fix all those combinations via Find/Replace. You would need to do a Find/Replace with, say:
Find = "^w
Replace = "
and stepping though each one, replacing on a case-by-case basis, following by a Find/Replace with:
Find = ^w"
Replace = "
and stepping though each of those, replacing on a case-by-case basis. There is simply no way Word can tell whether a given quote mark is misplaced. Yes, a Find/Replace expression could be crafted to look for certain patterns, but that would be thrown off immediately there was a mismatch - I've seen far too many OCR'd documents where quotes have been misinterpreted as some other character to assume they'd all be OK.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]