My 3GS (new bootROM) is on 4.1, jailbroken. I would like to upgrade to 5.1.1 incl. jailbreak, but as I don't have the SHSH blobs (Cydia only has 4.1, 4.3 and 6.0.1), is there any way to do the upgrade without iTunes? (iTunes won't let my, as Apple does not sign 5.1.1 any more, right?)
As the phone is jailbroken, I thought anything should be possible. Even sending a new custom FW?
I don't want to go to 6.0.1 because of the tethered jailbreak.

Thanks for any help?