Now I realize that very few (okay more like none) of our clients would ask for this but it's a good way to try (and learn) new things and expand your Photoshop skills.
Here is the finished image (click on it to view larger):
I took the original image -
and using layer masks overlaid it with a dried mud texture -
then took a small piece from a rust texture -
You can get these textures (and many more) for free over at CGTextures and you can walk through the step by step tutorial here.
