Hooray, it’s working! I’ve managed to get it working with Witty Text, don’t think there was ever a chance with wp_quotes!
I managed to get it working by specifying $before
as <p class="site_description">
as I had done before, but it works now because of your suggestion of adding the class #header p.site_description
to my CSS file.
Thank you very much vkaryl, I really appreciate your time and help! ??