I finally finished the broken ambrotype right before Christmas. I needed it for a Christmas gift for my Aunt. She had broken the photo when she was a little girl about 60 years ago - and for Christmas she got it back looking like new - maybe even better than new. The process required lots of clone tool, heal tool, and artistic patience. Obviously if there was a crack you have to cover that crack up with parts of the image that aren't damaged. Repair takes time and a good eye. I think the final outcome was pretty good.