Done it !!! i am on 3.55
A spanish member on demonhades helped me a lot ,he edited some files for my ps3 and uploaded them for me . . . after my ps3 bricked 2 or 3 (can't remember )times more ,i changed a file . . . then during a flash gave an error and hanged bliking green light forever ,i extracted the usb drive,powerd off the console,then powered on . . and the title ROGERO came Up!! although the flashing log gave and error (do you believe this??) system info spoofed to 3.70 . . . then i installed 3.55 ofw from recovery . . . . and then 3.55 cobra (i have the cobra key)
this guy on demonhades was really Great,never would have made it without him ,google translator was helpful also ,as he always wrote to me in spanish
still haven't tested the cobra key and other features to know if everything is 101% working but i think it is