Hi blyoungs,
Here is a quick start at it for you, would have been more useful without the graffiti
I used a levels adjustment layer and pulled in the blue channel slider to the majority of the info. Select the colour of the damaged area, new layer, fill, invert, change the blending mode to colour. Curves adjustment layer, raise the midpoint till you like it, add mask, paint back in the b/ground area. Cropped the image, but that will depend if the information on the left hand side is a necessary part of the image. Proceed with healing and cloning.