I found some time to work on this again and solved it.

The hint was in grub.conf, paths are relative to /boot

#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,1)
#          kernel /vmlinuz-version ro root=/dev/sdb8
#          initrd /initrd-[generic-]version.img

The only grub.conf on the disk was /etc/grub.conf. I copied the file to /boot/grub and the system booted normally.

Looking back at my question, I'm not at all sure how I ran sudo cat /boot/efi/EFI/redhat/grub.conf That is evident in one of my comments that locate grub.conf could only find the file in /etc

I found some time to work on this again and solved it.

The hint that finally caught my eye was in grub.conf: "paths are relative to /boot/"

# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,1)
#          kernel /vmlinuz-version ro root=/dev/sdb8
#          initrd /initrd-[generic-]version.img

My grub.conf file was in the wrong place, /etc/grub.conf. I copied the file to /boot/grub/ and the system booted normally.

Looking back at my question, I'm not at all sure how I ran sudo cat /boot/efi/EFI/redhat/grub.conf That is evident in one of my comments that locate grub.conf could only find the one file in /etc