I am going to assume this is on /dev/sda1 (if not mark the appropriate location and run this command )
Once you find an alternate superblock from that list - run a fsck against it.
dumpe2fs /dev/sda1 | grep superblock
My suggestion however would be to use RescueCD and start from there.
fsck -b 32768 /dev/sda1
we have this setup in our PXE booter.
If you have another node online - and want a copy of that PXE image - (kvm) let me know - has a few other distro's in it)
Make sure that /dev/sdxxxxx is not mounted of course
I have a feeling that this may have been mounted when you originally did the fsck.
(call it experience some years ago ... cough cough)
In the meantime - we are praying you get back up and running quickly.