Rails Unlimited offered a resin kit for the 1932 ARA car. I got one along with some 3D printed louvered vents from Bill Lane and turned it into a Seaboard Express car. Here's a photo of the real deal, I was taking photos of my model and the batteries quit and need recharging:
Here's what the kit looked like:
And the vents from Bill Lane. I think this photo showed O, HO, and N scale vents: