Where's my grub2?

[NoOp]

Sort of like 'Where's Waldo'...

Multiboot 9.10 & 10.04. Both have grub-pc (grub2) installed. However the
actual grub2 being used is on the 9.10. So here's my question:

Is there an easy command to determine which grub2 is being used?
For example if I'm in 10.04 and I send time modifying /etc/default/grub
nothing much will happen even if I use 'sudo update-grub'. Reason being
is that the system is using the 9.10 grub2.

Seems to be way too many grub- options to choose from anymore:
$ grub-
grub-bin2h            grub-mkfont           grub-probe
grub-editenv          grub-mkimage          grub-reboot
grub-install          grub-mkisofs          grub-script-check
grub-mkconfig         grub-mkpasswd-pbkdf2  grub-set-default
grub-mkdevicemap      grub-mkrelpath        grub-setup
grub-mkelfimage       grub-mkrescue