I had a hen with something similar in her mouth. She wouldn't eat. Nothing the avian vets tried worked. As it grew larger in size she had trouble breathing & I lost her. It was probably a malignancy. I hope you have a better outcome.
The Horse Barn Chicken Coop was designed to match our horse stable. I couldn't find a design, let alone plans, for what I wanted, so I gave DH my idea & desired dimensions, and he planned & built it out of a mixture of leftover & purchased materials. It has lots of light to help the hens lay...