I think I'll call this one done. The hair was easily edited for color using some browns, greys, and then ivory. I did add a bit of red to the shadows, and did a bit of finishing up on the dress.
Using the Fisher paper and polychromes, you could continue to tweak forever - it's a bit difficult to leave pencil strokes showing when you are accustomed to a completely smooth finished surface - but I like them, and this is more in keeping with the rest of my work.
Two things that I am not happy with yet.
1. It's difficult to keep the skin tones 'clean' when you are blowing dust from the other areas of the work. I concentrated on blowing away from the white dress and the skin, but I still feel like some of the dust strayed.
2. The darks want to flake off of the paper a bit - I think I'll wait until the very end to add background darks to any areas other than where necessary to keep the values correct to see if I can remedy this.
Finally, I really want to spray fix this, but have been cautioned about it.
On to the next project!