For anyone else that finds themselves in this situation....

After patching SLES in preparation for OES2SP3, the system failed to boot after rebooting. GRUB was updated.

A new stage2 file appeared in /boot/grub which was not in working condition.

I replaced the stage2 file with a known good copy from another server to get back up and running again. I used a SLES DVD in Rescue Mode to mount the volume and perform the repair.