This is really cool, I would love to do something like this just not sure I could build something that both protects the books from Texas weather AND can be easily opened.
I've seen several in towns I've lived in in the pas few years. The most immediate answer that comes to mind is an old children wardrobe. The doors can close, maybe you can add a strong magnet so it resists wind, or even a padlock with the combination written on the door...
You can also ask your town official if you may repurpose a payphone for instance.
You can also ask your town official if you may repurpose a payphone for instance.