Have comfort knowing that you did all you could do for Moe. The time and patience you spent with her is above and beyond what I couldve done.
You're caring and compassionate care is above reproach. You did the right thing.
I remember reading long ago that if you put a tooth in a bottle of coke, the next day it will be completely dissolved. I've never done it, but I know it does a number on my innards.
Crop surgery is an option, but it would be too stressful since the hen is at death's door. Also there's no gizzard surgery, and that's the main issue in this instance.
If she gets constipated, applesauce acts as a mild laxative in chickens.
That's severe impactation. You can try giving her tomato juice, it helps get things moving. However, I dont think it'll help in this situation. Good luck.