Sometime iPhone sold in china use the HW method for the unlock. They open up the phone and solder a chip to the commboard itself. This was the early practise before software unlock was made fool proof.

@drmere
Maybe u can connect the phone to your pc/laptop and try in DFU mode. Sometimes our pc/laptop can't detect the phone in normal restore mode but DFU mode can do wonders. Try that and see what happens. If not then maybe we can schedule a meet up.

@drmere
Sorry ... been busy lately. I think your phone still can be save. But I'm not 100% sure. Must take a look first then can know. If its true that your phone have been modified by hardware, i'm not sure what will happen when u upgrade. Need to dig back the info in my head. Forgot already about hardware hack.