Sorry for the late reply!
It won't solve all my problems, but I managed to get my IDPS number from PSNPatch!
I thought the xRegistry.sys file was related to my user accounts, and that if I didn't have it, if I were to copy the users over from my old HDD to a new HDD, it wouldn't work. Maybe I am mistaken.
If I were to copy the xRegistry.sys file that's on the HDD I used to install CFW, it would be different to the file that's on my old HDD that I can't boot with.
If I don't need the xRegistry.sys file, that's good!

I have all my data from dev_hdd0 from my old HDD. Now I just need a way to be able to restore that on a new HDD, and then install OFW, and be safe to log onto PSN. I read the link you sent on post #15, so is the only way for me to copy my data over through Linux? (I'm really sorry for all my questions)
Even if I restore the data I got off my old HDD and my trophies aren't restored, trophies should be able to sync as usual when I log into PSN, right?
That's okay. Your tools have been very useful, anyway! I also found your Arch Linux Virtual Box image you posted on another forum, and tried to use that, but for some reason, when I ran the mount_fat_nor.sh, at every line it said "command not found" so clearly I did something wrong. I have the hdd_key.bin and vflash_key.bin in the right place.
I opened up the sh in a text editor, and tried to enter the terminal commands manually, which worked until line 6, which was "cryptsetup create -c aes-cbc-null -d /home/picard/ps3hdd/vflash_key.bin -s 192 -p 8 vflash_dec /dev/mapper/ps3hdd_dec1"