So my b-n-law thinks he is being smart and upgraded his sons unlocked 3GS (via unltrsn0w) to 5.01. He has dropped it in the mail for me to look at and I need to know where to start.

Thoughts are:
Downgrade to 4.0.1 (or another old one)
Upgrade to iPad BB (if I can)
Then upgrade/unlock

Will this work or has the BB been upgraded above iPad level and it is now an ATT iPhone or a fancy iPod?

Thanks