The /private/etc folder is the same folder. /etc is an alias or a symbolic link to /private/etc.
You just need to restore the contents of /etc/apache2/httpd.conf and /etc/apache2/extra/ with the contents of /etc/apache2/originals/
In terminal, like this. (4 commands)
sudo serveradmin stop web
sudo cp /etc/apache2/originals/httpd.conf /etc/apache2/
sudo cp /etc/apache2/originals/extra /etc/apache2/
sudo serveradmin start web
If this doesn't work, the likely there's other issues at play.
Oh! Don't mess with the config files. The GUI doesn't like it! If you have to use the terminal you should make as many changes as possible in the GUI first. ONLY THEN change the config files. Abandon the GUI completely after that. Changes made here will mess up your command line work.
I can't see anywhere in the GUI to change anything to do with apache, that would be awesome. Is ther such an thing and if so where???
there was no serveradmin command on my machine, so i stopped apache with apachectl
but I copied the files from original folder and the restarted apache
but still couldn't get to localhost.
I looked at error_log and access_log in /var/log/apache2 the last entries were from Dec 2012, but nothing in them ecxcept things like a missing favicon.
So I look into apachectl to see if i could find anything and apachectl -t led me to a syntax error in a conf file in the /etc/apache2/users/ folder. It was a typo, <Direcory> instead of <Directory>
Once I fixed that I can at least see localhost, although what I wanted to do was set up a few vhosts and I'll probably break this again trying to do that unless Apple has a GUI for that.