I am not sure if this is allowed here but I searched and found a blog that had different Ipsw's already PWND, they had 3.1 hacktivated as well as a 3.1 unactivated for ATT customers, they both had cydia and they both preserved your baseband. I can PM you the link. Just make sure you use the right Ipsw. There are different ones with different options and devices. The one I used was 3.1 for the 3GS unactivated as I am an ATT custumer.
Can I have the link to the blog which u download the pwnd please. Thank you
