OK Ron, I got questions.
First, where did you find ¾ 4x8 Oak plywood for 12.27? In Lowes and HD, ¾ AC pine is over $20. The oak veneer plywood is over $50.
You said titebond III is waterproof. I’ve been wondering what the difference was between II and III. I looked at Lowes today and they only have the original and II. I did see a 16 oz bottle of III at HF for over 6 bucks. The gallon of II at Lowes was around 17 bucks. I’m not sure waterproof is an issue for mine. I’ll use glue and screws to apply the top, front, back, and the plywood will have either spar varnish or fiberglass resin as a primer (double on the edges) before putting on an epoxy or poly enamel finish (2 coats).