I was just about to link that, lol. See if the method I helped iisforiphone works for you. You are already in recovery mode, so you are 1/2 way there in the whatever jb tool you use because all jb programs (besides jailbreakmedotcom) require dfu. Limera1n for iOS 3.x requires recovery mode then dfu (which till this day makes no sense). So in all essence, you're almost there.
However, the iPad baseband for the 3G is one avenue I have not ventured yet, but let us know what happens. Good lucky buddy.