You never heard of Hantavirus?
Only an EPA certified Haz-Mat team should have cleaned that interior. Or a respirator at the least. Seriously, you shouldn't have handled that stuff.
From my experience of making the wrong decision 100% of the time, keep the car. You'll thank all of us later.
Edit: In Mexico, you'll be with people, who wax their 50's/60's daily drivers every day.
You brought up a very good point. There are genuine Sanden compressors and there are Sanden style Chinese compressors. Don't let the price of the Chinese junk entice you.