First is a good photo of Beakie Lyn.
Many moons back my folks had a maggie in the same situation. It seemed to get by okay. Can't comment on the long term condition of the bird because my parents moved.
We have a female king parrot that turns up that has lost her bottom beak. For a seed feeding bird this is devastating. We smash up husked seeds that she can pick up with her top beak and tongue and this seems to work for her.
We are thinking about moving house and I worry about what that means for this bird.