I've got a 3G (3.1.2) that is JB and unlocked. It's originally a Spanish iPhone, I'm using it with a UK SIM and don't have the Spanish SIM. I also am a bit of an unlock idiot, thus the question. Can I restore this phone? Or will that restore it to its unjailbroken state? If so... what should I do before selling the phone on? Cheers for any pointers.
The firmware on a 3G can be updated and downgraded as wished and jailbroken on any version. Don't know what type of unlock you have (software or factory) but if you upgrade to 3.1.3 firmware your baseband will be updated to 5.12.xx and you cannot software unlock. Stay at 3.1.2 if you restore, the re-JB with Redsn0w, unlock with Blacksn0w.
I think it was done as a software hack (it has cydia and blackrain on it) To use pwnage tool to restore, I won't need a movistar sim, is that right? Thanks for all the help.