Sorry to sound like a total noob here, I've tried looking but can't find my answer, I'm after restoring to the same firmware I'm on now which is 3.1.2 my shsh blob is stored on cydia, btw I'm on a 3gs old boot rom, I'm after restoring to 3.1.2 again the baseband im currently on is 04.26.08, I am aware that apple has stopped signing the 3.1.2 firmware, I'm just wondering what I have to do to retain it's unlocked status and also to bypass apple signing of the firmware so I can restore to 3.1.2,

Thanks for your time

Be gentle lol

Check the stickies or search for TinyTSS or Firmware Umbrella. Both of those will do what you're asking (allow you to restore to 3.1.2). Once done, use redsn0w to jailbreak (make sure you know whether you have a new or old bootrom, this is IMPORTANT and you WILL be asked) and use blacksn0w RC2 to unlock.