Thanks Nicole.
You know what I just realized? I completely forgot to tell you how I did it. D'oh!
Well here goes; I used variety of different soft edged (fuzzy) brushes in combination with The GIMP's clone tool to clone out as many of the scratches and spots as I reasonably could. I chose the soft edged (fuzzy) brushes because their edges tend to blend easier with the rest of the image.
That was it, nothing fancy at all, just lots and lots and lots of cloning.