Export theme for single page from code?

Wondering if it is possible to, from code, export the theme configuration XML file for a specific page in a group.  I am working on something that resembles a CMS plugin, but need to track revision history.  Since most content will be entered via Generic Content widgets, I thought one way to save revision history would be to enable a button that says "Archive This Page" which would essentially trigger the export of the page config and save it to a database.

I'm using a custom route via IApplicationNavigable and Group is the application type.