OS X 10.8 or later. This script will look for an image file in the parent folder of each selected track's file--presumably its Album folder in which you have previously placed an image file of some sort--and apply the data from that image file as artwork for the track.
Re-associate batch of dead tracks with files from selected folder
Display, create text file listing info of dead tracks
Renumber order of selected tracks
Two scripts copy text from clipboard to current or single selected track's lyrics tag
Perform search-and-replace on text in your choice of tags
Exports and then re-imports selected tracks' artwork