Ext3 emergency recovery

[Adam Atlas]

I have a damaged Ext3 filesystem which fsck has not been able to  
recover. If I try to mount it, I get a message like this in dmesg:

   EXT3-fs error (device sda1): ext3_free_blocks_sb: bit already  
cleared for block 2370866

If I try fsck on it, I get a series of messages like this:

   Inode bitmap for group 0 is not in group.  (block 0)
   Relocate<y>?

Up to group 95. Some say "SEVERE DATA LOSS POSSIBLE." I backed up the  
filesystem and tried answering yes to all of them; it ended up just  
erasing the whole thing. So I have a backup with the data intact but  
with a broken filesystem. (Unfortunately I don't have a backup from  
when this filesystem was working.) Is there anything I can do now to  
repair the filesystem, or at least recover some data?