I have recently received a different repaired Iphone from Apple (serial 7U728) because of a battery short in original iphone (serial 7S728).
I did the Call *3001#12345#*
and it says I have firmware 04.03.13_G (which seems to be 1.1.3).
I do NOT know whether I have the original 3.9 Bootloader or If Apple repair also upgraded the BL to 4.6? Is there a way to tell which BL ?
Then Is it possible to restore this phone back to say 1.1.1 & unlock/jailbreak it?
what method would you recommend as most reliable?