Choosing between internal and production version of page

I develop an administration interface of website. In "live edit" mode user can browse the website and edit pages (mostly texts). Website is presented in default production design to user and only small bar with close, save and revisions buttons is shown in the middle left of the screen. Users can save the page as Production version (and overwrite current page) or as Internal verion. There can be only one internal version which is shared among all the users.

When user navigates to the page

• should I display current Internal (if any) or Production version by default?
• how should I let user clearly know which version is currently viewing?
• how should I let user choose between versions?