Currently Being ModeratedMay 18, 2013 2:57 PM (in response to RobMonroe)
Normally I'd start with this...
Use Shift > View > Show Exact Duplicate Items as this is normally a more useful selection. You need to manually select all but one of each group to remove. If you have multiple references to the same files then don't send to the recycle bin. Use my DeDuper script if you don't want to do it by hand, or want to preserve ratings, play counts and playlist membership. See this thread for background and please take note of the warning to backup your library before deduping.
(If you don't see the menu bar press ALT to show it temporarily or CTRL+B to keep it displayed)
...but the the current implementation won't cope with the missing files that you've removed by hand. I've planned a rewrite that will merge playlists and playcounts when some of a set of duplicates are missing, but at least one can be found, however there always seem to be other uses for my time. What ought to work however would be to fix the broken links first with my FindTracks script, then use the DeDuper script as above.