If the imgur image is the full resolution, I don't think it can be salvaged. I tried several Photoshop tricks, but the left three columns just don't have anything to darken in a lot of places.

You might get something if you put it in photoshop and fuck about with the contrast and brightness levels, use the sharpen tool etc and see what it does, but tbh looking at the image I think you might struggle with most of the faded bits.