I’m using a battery holder that will use 3 AA batteries. I had to create a door and make it simple to remove. On the backplate of the shell, I also made a housing for the battery holder. I’m thinking of making the backplate mount all the electronics, but the front part of the shell will have holes that will allow you to attach both parts of the shell together.
I will probably smooth everything out everything and will update you on this project once I start on sound and the controls. Have a good rest of your day.