Help re mixed paths in a library

Hi guys - just registered to ask this; been a reader of the content for a while now.I'm in the middle of migrating to a new desktop, so want to take the time to fix something that's been bugging me for a while:

Old computer - XP, New computer - Win8.1

Itunes ver that updated, "last touched" the library - 11.0.5.5; ver of itunes migrating TO - 11.1.5.5

So: all media files reside on a NAS, using iTunes organization. The iTunes app runs locally on our computers with individual itl files for each user and each user account (IOW, I have two lib files, one on desktop one on laptop; the desktop is where I do all device management). Each person's library has iTunes pointing to the media files on the NAS. I do all admin, so I am careful about not having multiple sessions of iTunes attached to the media.

Problem is, when I set up the nas a couple years ago, I first set up my own library using the UNC path for the media files (hadn't mapped the drives yet). BUT I set up my wife's library using mapped drives. Then I imported some playlists into my library that had originally been done with the mapped drives, so I get duplicates. Is there a way to unify the paths within my library files so that all are mapped lettered drives?

Thanks for any help,
Squirrel