I'm currently on a jailbroken 3.0.1 3GS. I know how to JB, preserving my baseband while doing so. I also know how to restore a device to stock firmware. But it's not clear to me what will happen to my baseband if I choose to restore my device. I'm planning to upgrade to 3.1.2 (jailbroken), retaining my old 3.0.1 baseband. After the upgrade, are there any options to restore to a stock firmware without affecting my baseband? Note that I do not have a 3.0/3.0.1 ECID SHSH on file with Cydia, so a downgrade to older stock firmware will not be possible. Any suggestions, or should I just resign myself to upgrading to the 3.1.2 FW's accompanying baseband?