So in the spirit of the Photoshop frenzy that is gripping the Joe domain I had another hack at the 3D pages. After a great deal of trial and error I managed to bleach out the green and darken the red before cleanup. They're still pretty dire but might be saved with a splash of colour:
I had to abandon page 1 of River or Serpents though, as the lettering was obliterated. Maybe a higher res. scan is the way. Does anyone have any suggestions?