Okay, I'm getting somewhere.
It seems the steps that are missing are after 'sudo apt-get install grub', you also need to run:
While will create the menu.listCode:sudo update-grub
I'm not as familiar with grub, but it seem you also need to run:
Which looks like it will fail, but will generate the device.map for you to edit.Code:grub-install /dev/mapper/nvidia_dhfedfae5
Although I'm a little hazy on whether that should be aimed at the partition or the hdd itself. (i.e. remove the '5' at the end).