At my friend Caitlin's suggestion, I used Simplicity 5581. I think the sizing runs big, so if you're not sure what size to make, I think I would size down. My husband is usually a solid medium and I think the resulting shirt is a little big - but on the other hand, Hawaiian shirts are often layered and are supposed to be roomy.
I found green vintage buttons in my stash to go with the mid-century color palette and theme. I'm really happy with how it turned out! I need to get better pics, but for now....
