For one, losing in a civil trial isn't the same as being subject to criminal penalties, so you can't self-incriminate unless what you're hiding would itself have been a crime - many contractual disputes have no criminal dimension whatsoever and so your liberty isn't at risk.
But more to the point, archive.org already has a copy of what you previously made public, and there's no reason to burden them with the expense of manually retrieving it as they're not party to the case, and it would be wasteful of the court's resources and archive.org's time to make them sue you for the expense involved.
Here's a more detail breakdown of how the 5th applies in a civil litigation context: http://www.litigationandtrial.com/2013/04/articles/attorney/...
The bottom line is that the 5th can help you stay out of prison, but you can't use it just to avoid losing a dispute.