Magento Missing HTML Head, Header & Footer in Admin > Design

I'd recently made a change to a magento installation so that I could use custom page layouts. During this I copied a file from a core directory to a local directory:

/app/code/core/Mage/Page/etc/config.xml

to

/app/code/local/Mage/Page/etc/config.xml

I then found out in the CMS is was missing some functionality:

Admin > Configuration > Design > { Missing } Head HTML, Header and Footer

To the regain this functionality, in the core folder above you have to copy both files, config.xml and system.xml over as you are switching the functionality from the core over to the local directory.

The original post I got this information from: click here