Thanks... however that didn't work.
I did figure out a fix...
1) Deleted the greyed out songs (it didn't ask me to "Move to Trash - so like you said, the files weren't found)
2) Logged into iTunes and clicked the "iTunes Store" link.
3) In right hand column I clicked on "Purchased".
4) Selected "Music" downloads and on right hand side selected, "Not in My Library".
5) It allowed me to download them again!!