Yeah I figured they were older, but I also couldn't really believe it when I first realized they rotate. Thanks for the clarification.
Anyways, here's the Dauntless engine, supposedly a Wright R-1820.
I could've made the cylinders more rounded, but eh, I was worried the cowl would hit it and there is nothing to fill the gaps that would've formed.
Here are all the segments, some glued, sitting beside each other. I need to do some more prep work before gluing them together, like attaching the prop.
Luckily the USAF insignia came out fairly aligned, but it's slightly off on the other side.