I have an iPhone 3g previously running 4.2.1 firmware, jailbroken with redsn0w, and baseband at 6.15.00
I was going to sell it so I went to the reset portion of the phone and did thee "erase all content and settings". after this, I go to restore and nothing works. phone goes into recovery mode and evertime I try to restore I get a "1015 ERROR" please help....
You will not be able to restore to stock firmware.
You have to put the phone in pwned dfu mode and restore to custom jb ipsw.