Facebook has just launched the feature for its users that they can limit the visibility of old facebook covers to their contacts which they chose to.
The old facebook covers can be shown to public, as they were before, or they can be limited to friends only or specified people. Or you can chose “only me” as an option. The same options which were there for other pictures of your profile.
The tool tip announcing the release of this wonderful and much needed feature says:
Tip: Now you can change who can see your old cover photos – just go to your cover photos album. You can change the privacy on each one.
You simply need to open that cover and change the privacy settings by clicking on that “world” icon (showing that image is currently visible to public) and then change it to whatever you would like it to be.