The large format scanner we use at work is a dream!  These scans turned out better than I had ever hoped they would!  I did have to scan in 4 sections and piece it together.  Guess it is a good thing I decided against going huge scale.  In any case, here is the final painted image for the cover with minimal Photoshop trickery.  I did punch up the contrast a touch and the saturation just a smidge.