This script will export then re-import the artwork data of the selected tracks.
NOTE: this script cannot handle processing more than about an album's worth of tracks per launch due to the way iTunes manages the graphics data.
For OS X 10.6 and better only.
Create a playlist for each entry of a specified tag
Display, create text file listing info of dead tracks
Exports and then re-imports selected tracks' artwork
Copy Artist to Album Artist of selected tracks
Remove iTunes tracks disassociated from files
Set year of selected tracks to their release date's year (if available)