[Zope] Recovering from bad backup...

Hello all. I'm trying to get a zope application out of a tar backup of the entire zope directory. Unfortunatetly the file data.fs is not in the tar. (Maybe zope was running when the backup was made?) At anyrate the files I have in the /otp/zope/var/ are data.fs.lock data.fs.old data.fs.tmp is there some way I can recover from one of theese?