"Changelog" and/or Version Control Plugin

I've searched far and wide, installed a few plugins and then uninstalled because they didn't do what I wanted, so now I'm coming here for any help you may can offer.

What I'm looking for is a WP plugin (or other workaround) that works something like this:

1. A post or page is published. This is assigned a version number such as 1.0.

2. That post or page can be updated by site administrators to correct errors, add more information, etc.

3. Once it is updated it replaces the version 1.0 post and now has a new version number 1.1.

4. The original version 1.0 post is available for review to compare what changes have been made.

A real life example of this kind of usage would be selling an ebook that is broken up into posts. Customers get updates for 6 months let's say. The customer would surely like to see the new most updated version but in some cases they may want to compare the new version with what they have been using or what they originally bought.

There are plugins that allow you to merge changes into the original post but once the merge is done, the original isn't available for review by the customer OR the administrators. In some cases, an update may need to be undone if the updated information is found to be wrong so having access to the original is important.

Thoughts?

Thanks in advance.

Mark