So you have your key or you don't

If you do use FW toolbox to insert it into a Hitachi 78 FW and flash that fw to the drive, now if you do not have the key you will need to get it from the old drive...depending on how bad it is you may be able to still hook it up and dump the firmware, get the key and use fw toolbox to put it into the new drive. But if you are unable to hook the old drive up because it is to badly damaged then what you will need to do is de-soldered the SST chip and dump it with a programmer, get the key and use FW toolbox to do the rest.
gigabite