Still not using UEFI. Should I?

[Virginio Miranda]

Not necessarily:
https://superuser.com/questions/1165...rtitioned-disk

Your setup is the second one: "In this variant, the first stage of GRUB still resides in the MBR"

" BIOS-mode GRUB on MBR -- This is the traditional PC configuration. In it, GRUB is split into multiple stages. The first stage resides in the first 440 bytes of the Master Boot Record (MBR). This first stage then loads and executes a second stage of GRUB, which typically resides in the sectors immediately following the MBR. This space is officially unallocated on most MBR disks, so putting GRUB code there is a bit risky; but it usually works OK. Additional code resides in files, typically in the /boot/grub directory of the OS used to install GRUB. There are numerous variants on this configuration possible. For instance, putting the GRUB first stage in a Partition Boot Record (PBR; the first sector of a partition) was once popular, but is pretty uncommon today, and in fact I'm not 100% sure that modern GRUB 2 still supports this option. "

Only for clarification:

This method still works on modern GRUB2. I still use this ancient method.