I tried this using flora's instructions only i didn't convert to black and white.
I made a new background using black to white gradient set to difference mode.
masked the face and used flora's high pass filter instructions to get rid of some of the cracks. I removed the stain, color bleed from the hair and recolored it using a blank layer set to color mode. I replaced the dress with one from the internet. its still pretty grainy but i am still learning. I forgot i had a standalone version of neat image. the second photo was run through that.