I found it's final form!

Well, that came together rather nicely.

For not having a single straight line on the cooler and looking pretty crooked half-way through, this thing rounded into shape pretty nicely.

One big help: even though it's the same area to cover, I realized it would be easier to put the bottom shelf supports on the side and cover it with long boards versus supports on the wide side and many more short boards. Saved me some time and it was easy to cheat that last board to look straighter when compared to the bottom trim. At least I realized it while I was still working on it vs after things had been sealed and left outside for a while. And that's why it's usually better to have a plan.

That trim saved me a lot of headache too. Much cleaner.

The many short boards approach was alright for the lid, although it did leave some oddly short openings to cover to keep everything symmetrical. It looks better completely covered though vs leaving evenly spaced openings.

That did make the lid a lot heavier, but it still balances to stay open.

There's still lots of sanding to do, and seal, but if I can get this out to the porch next week there's lots of other stuff I can poly on my first Friday off. Sounds like a good way to spend the day to me.