Q: Match created tons of duplicates that aren't visible in iTunes

I'm a Match and Music subscriber, and downloaded all my music on the cloud (music on iCloud wasn't downloading to my iPod Classic, this was an attempt to fix).  Match proceeded to create duplicates of all my music, and added a " 1" file extension to each, making my ~160GB library now 320GB and filling my hard disk.

iTunes however doesn't show any duplicate files, so View> Show Duplicates and View> Show Exact Duplicates doesn't find any.

I can see the duped files opening Music/iTunes Music in Finder.

And iTunes seems to only know about the ones with the " 1" extension.

Any suggestions on how I should repair my library?  I know I can delete all the music in iTunes, delete whatever remains in the filesystem using Finder, and I don't totally trust Match to not lose music or myself to overlook something irreplaceable.  Any other ways or suggestions?