Well, if you have the replacement hitachi, you simply flash the firmware as you normally would and then you use flashsec to flash the sector which contains your key - I dont remember the sectors off hand but if you get a replacement drive, just ask. Then, it will work in your 360.
You could try using the two wire method to force your drive into modeB and see if that works. THis method is described in the tutorial.
Caster.