Help please: I screwed up my iTunes Music directory by moving it back to my HD

Question

I recently bought a Nifty MIniDrive and a 64gb SDHC card so that I could move my ~32GB iTunes Music folder off my hard drive.
I don't know why, but it just doesn't work. Not even close. The music files that iTunes copied over to the MiniDrive just won't play. Not even via QuickLook in the Finder or via any of my audio editing programs. It's like I bought a "write-only" drive :-/. I'm in contact with Nifty to see if they can fix that end of the problem. Otherwise, I may have flushed $75 down the digital toilet.
I decided to give up and move back to the original drive, so I followed Apple's instructions for moving the iTunes Music folder (again). In the process, it copied all of those damaged files back to my hard drive (now dangerously full!), renaming them as "<Original Song Title> 1.mp3" (adding "space-1" to each filename).
Now I've got two copies of all of my nearly 5,000 songs, with most of them unplayable copies.
Good news: the original files are still there, and are still playable.
Bad news: I have no idea how to tell iTunes to use the original copies of the songs, rather than the "space-1" copies.
I thought about editing iTunes Music Library.xml, but that will probably end in tears.
Does anyone have any advice, other than laboriously deleting all the "space-1" copies and, one by one, selecting the right songs in iTunes when it notices that the media file seems to be missing?

Answer 1

Here's the direction I think I'm going with this…
Using something like the script described in Changing the path to a file in iTunes with AppleScript from StackOverflow, I'm going to try to modify the paths of all the songs in my library to the version that doesn't have "space-1" before the filename extension.
Of course, I'll back up the library files before doing this.
I only wish I'd backed up my iTunes Music folder before doing the back-and-forth to the Nifty drive.