I really enjoy fuyu persimmons. They're one of my favorite fruits... although I enjoy mostly any fruit.
So when you're grafting, I thought you needed it to be at an angle, and then you slipped in under a spot in the trees bark. That's remembering from a long time ago though. It looks like you just cut then square and then electrical taped them together. Did you put anything in between to encourage bonding? Is that even a thing? I thought there was some paste (not glue), but some kind of paste that you could put there.