I want to preserve my baseband (02.10.04), even though I know there is no unlock for it yet and that a future unlock is probably for newer basebands also. Just in case.
However, when using redsn0w, my baseband isn't preserved, is it? Then how do I jailbreak 4.3.1 with baseband preservation?
You need to build a custom IPSW with PwnageTool. Be advised that on the older baseband your signal strength will always show as 1 bar, even though you may be getting a stronger signal. MuscleNerd says an update via a cydia package will be released soon to fix this.