Error in my thinking?

[cindra]

I'm having an iTunes crisis here (who isn't? )

I had to send my computer in for repair. I got it back and put all my backed up stuff on it. I downloaded and installed iTunes, and of course it searched my whole drive again for music. I started and stopped this several times trying to get it figured out, and as a result have dupes, trips, many multiple copies of the songs on there.
(More info--I have always had it set to manage my own music, so I am ass-u-me-ing that even if I royally mess up the iTunes part, the music still remains on my drive. I've only purchased 3 songs from iTunes.)

In order to eliminate these, here is my thought (and if I've not got my brain straight let me know before I dupe again!)

1. Enable the "Date Added" column in iTunes.
2. Keep everything older than the date I got the computer back.
3. Keep any songs purchased between then.
4. Delete the rest.

Could it be that simple?
TIA for any confirmation/suggestions.