Hi, I have a 2g on 3.1.2 that I Jailbreak'd and unlocked using Pwnage Tool. I'm no about to sell it and wish to reset, and Jailbreak it again.
I still have the custom version of 3.1.2 that Pwnage Tool originally made so I'm wondering if it's OK to simply restore the phone via iTunes using this custom firmware file, or if I should first reset it back to a non Jailbreak'd version of 3.1.2 then Jailbreak it using the custom file. I hope that makes sense!
Use your custom made file. The only difference between the two is that you will have saved about 20 minutes (from restoring to a legit format and re-jailbreaking it). If you were to sell it as a non-jailbroken and locked phone, then you should restore to default settings otherwise, the custom file will do.