It doesn't look good. The best thing you can do is to just make him comfortable. Make sure there is plenty of water and keep him in the incubator. Don't mess with him any more. I don't think he is going to make it. Sorry.

The cut looks awful big. And if you did that at day 51, they may have been exposed too much to the elements. Hard lesson to learn. Wish there was something I could do or say to help.