Restored my Macbook Pro but my iTunes content was saved on a separate partition. When I re-setup iTunes the status bar reports 30gb less content than my iTunes Music folder. How can I find what is 'missing'?

My Macbook Pro software was failing and the Apple Store was able to restore it without removing the partition on my hard drive that contained most of my files including all my iTunes content. Initially when I re-setup my library I simply went to file--> add to library. Shortly after I realized that was essentially copying the library to the other portion of the partition because I forgot to change the location of the library. So I deleted the content already copied & then I re-setup the library, by asking it to be pulled from the previous location using this pages advice: iTunes: How to open an alternate iTunes Library file or create a new one

It appeared to work & everything I thought was imported. But on closer inspection, it appears that I have 30gbs less appearing on the status bar in the iTunes app than I do when I pull up the info on the iTunes Music folder in my finder. I'm not sure if this means somehow I have 30gbs of duplicates in my finder folder or if (most likely) I somehow didn't fully import the library from that file. Any advice? Is there a way to restore iTunes to factory settings again & set it up correctly this time?

Also I never actually trashed the original content I accidentally transferred to the other drive but when i skimmed those in my trash bin it appears they ARE indeed in iTunes, so I have no clue what didn't actually import. Any ideas?! I'd greatly appreciate it!