As per my information you have to use following steps to recover broken iTunes links.
First Make new playlist in iTunes with all lost songs -> Now Export the playlist with an XML file -> now Edit the XML file -> You can get this link using following string
Code:
"<key>Location</key><string>COMMON_PREFIX/UNIQUE_PATH</string>", so replace "<key>Location</key><string>INCORRECT_COMMON_PREFIX" with "<key>Location</key><string>CORRECT_COMMON_PREFIX"
Now go to File option and then Import the modified XML file.
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