This is a desktop PC. We run about 900 Sun / Oracle servers in our shop - all in production.
Feedback on the solution:
The system was rebooted with the live CD.
gparted showed the HDD as /dev/dsk/c7t0d0p2
Partition Filesystem Size Used Unused Flags
/dev/dsk/c7t0d0p1 unknown 255.88MiB --- --- bios_grub
/dev/dsk/c7t0d0p2 unknown 465.50GiB --- --- ---
/dev/dsk/c7t0d0p9 unknown 8.00MiB --- --- ---
p1 needed to be made active.
Root access was obtained (jack@solaris) password solaris.
# format > fdisk > 2. Specify the active partition > type "1"
A reboot took the machine straight to GRUB - thank you.