3GS 3.1/5.11.07 unlocked no WiFi -> 4.3.3

[bbrian]

My mother's iPhone's Wifi stopped working so it's up to me to fix it. If I understand correctly, I should use Pwnage Tool to upgrade using a custom IPSW. If I do that, will the iPhone still be unlocked from earlier or will I need to run an unlock again?

I think this is the guide I need:
iClarified How to Jailbreak Your iPhone 3GS Using PwnageTool (Mac) [4.3.3]

[iYeow]

Yes, you should restore to custom firmware and install Ultrasn0w again to unlock.