I'm sorry you lost the Orpington
If you work with the skin flap and it still doesn't stay, then it will eventually dry up and fall off on it's own.
The wound will granulate and new skin will eventually cover the wound, most of the time, new feathers come back in too.
This does take time, so take a breath, you've got this!
A couple of thread with a few photos of severe injuries, the healing process, you may find these helpful.
https://www.backyardchickens.com/threads/dog-attack-injury-graphic-pictures.1654172/
https://www.backyardchickens.com/threads/fox-attack-large-wound-on-side.1665400/