im guna have a guess and say about 3.42/3.50 at most
what your plan m8
right what i would if it was me when you get the other ps3 downgrade it to where you can remarry blue ray then try the one from you broken ps3.
See if it still works if so then you no that the blue fine but then after that i would put back the blue ray from the broken ps3.
Go into recover mode and slap on 3.60 fw update that one if all thing are good you got one for online and then one you waited for can run homebrew that my idea dont no if it will work tho but it worth a try i say
right what i would if it was me when you get the other ps3 downgrade it to where you can remarry blue ray then try the one from you broken ps3.
See if it still works if so then you no that the blue fine but then after that i would put back the blue ray from the broken ps3.
Go into recover mode and slap on 3.60 fw update that one if all thing are good you got one for online and then one you waited for can run homebrew that my idea dont no if it will work tho but it worth a try i say