Back-up of deleted revisions
On the dumps page, there is a non-public file "Deleted page and revision data. (private)" [1] which i would assume would contain such information. Well I wouldn't be surprised if back in the day it wasn't backed up, I would be shocked if that still was the case.
Someone like ArielGlenn would probably be a good person to ask.
http://meta.wikimedia.org/w/index.php?title=Meta:Deletion_policy&diff=next&oldid=340788 I would actually be surprised if this was true even in 2006. I could see it being the case pre-1.5, back when deleted revision text was stored in a separate table, but that's 2004-2005.
I've checked the earliest deletion log entry at meta which is this and I can see content inside; however I can't say the same for very old images that once they were deleted they got lost forever (note there's no "file history"). Best regards.
