I've tried googling 'flaying', 'flayed', 'skin' and 'scar' in various combinations, and I've read the wiki article on flaying and one very graphic article called 'Severe Accidental Flaying' (seriously, don't click if you have a weak stomach, there are pictures) but everything I've found so far either assumes skin grafts are possible, or alternately that the victim is completely flayed as a method of torture/execution, and therefore no healing is going to happen. I also tried looking for 'scalping', since I know that some people survived that, and saw some pictures of the scars that resulted, but I'm not sure how well it would translate to a hand.
Thanks in advance for any help!