Thanks for the quick reply.
It doesn't look like I can unlock the bootloader due to it not being allowed (Bootloader unlock allowed: No).
However, I could install cyanogenmod 12 (lollipop) using this method (warning, it most likely played a part in me needing this tutorial!).
It mostly worked, except for cellular data - which may be fixed at some point.
In case it helps anyone else, the cause of my bricking was:
- Rooting the device (step 1 of this)
- Install Clockwork Recovery (step 2)
- Wiping to factory using Clockwork Recovery
- Installing cyanogenmod 12 (step 3)
- Install Google Apps (step 4)
- (normally use the device for a while)
- Wiping to factory again
- Attempting to install cyanogenmod 11 (using step 3, but substituting with a download from the main cyanogenmod website). The install failed.
I have a backup of the original system using clockwork, so I'll reset back to that.
Unfortunately, I don't make a backup of the TA partition, so I'll make do without the special features.
Thanks again!