Thanks, @FridayYet , it was so wonderful because he was so good and most avian vets never see (or have never treated) anything but cage birds.
Peanut is going to be okay -- I was really worried because he split his lower beak lengthwise and broke a wedge of it out. My fault, really, I hadn't noticed the top beak was in need of trimming. Dr. Hudgell said it is fairly common. He explained the full range of possible beak repairs, from trimming to stainless wire and rebuilding the beak from synthetic materials -- wow!
When he examined Peanut, he figured out that it wasn't as bad as I feared. He trimmed it up, smoothed the edges, and asked me to continue doing that every couple of weeks until the bottom beak has regrown the damaged part. Phew, what a relief. I was worried that the split lower beak would interfere with his ability to drink water, or would spread further apart and farther down, but the vet said the tissue is holding it together and it isn't far enough down to prevent or interfere with drinking. What a relief! I hatched this bird from an egg -- I sure didn't want to have anything happen to him.
And now I know how to trim everybody's beak, because he carefully showed me, yaay x2!
Apparently he does everything from poultry to emus & ostriches along with cage birds and raptors. And bird rescue work. (Dr. Atkinson does rescue avian work too -- she treated one of my peas with a ruptured eyeball two years ago, and she was quite good also.)
I had ended up at a different vet clinic a month or two ago, with a slipped tendon peachick -- the avian vet there had never seen any peas before, and didn't really know what to do. Eventually she figured out something that worked, which was good, but she was really uncertain about what to do with it. So not going back to that place. There's avian vets and avian vets