Thanks, all, and with the help of the other admin, the system is up. What I had to do was linux rescue, the chroot /mnt/sysimage, grub-install /dev/sda
What I didn't get until later was it also needed /boot/grub/grub.conf, and then ln -s /boot/grub/grub.conf /boot/grub/menu.lst ln -s /boot/grub/grub.conf /etc/grub.conf
and it now boots. As I said, *so* much easier than editing /etc/lilo.conf, and rerunning lilo....
mark