WWII Magazine has a great set of infographics by Max Gadney on their website. They cover various weapons, equipment, and vehicles, as well as comparison charts like the one above. These are great for adding that extra touch of realism or finding that extra bit of inspiration for your dieselpunk story.
Some guy bolted part of a fighter plane fuselage to a WWII-era or -replica motorcycle. It is awesome. That is all.
If one single design aesthetic must be chosen to represent dieselpunk, I would choose streamlining.
It came to me instantly. As soon as I finished reading Zagglenack’s recent post, I knew I had to write about streamlining. Those flowing, organic curves, the cab set waaaaay in the back of the car, and the performance difference that can be achieved by applying a few simple principles of aerodynamics make for a beautiful example of form-follows-function design.