Try creating styles to accomplish each of the variations described here. If the markup needs to be changed to make the variation easier or even possible, it will be noted in the text.
In the "Mansfield" design, try changing the backgrounds (and background colors) around. For example, you could use the washed-out background for the title, the faded image for the masthead, and the basic image for the body. Don't forget to change the colors, too!
In the "stormclouds" design, change the placement of the background images so that they're all centered horizontally within their elements. Make sure they all continue to line up with each other.
Change the "stormclouds" design as discussed in the "Pros and Cons" section, altering the markup slightly and rearranging the styles so that the visual outcome is the same but the layout is more resistant to text wrapping in the title.