Here it is - Atlantic Republic, a sea power halfway between New England and Iberia, Brazil and Dakar, stretched from the Northern latitudes to equatorial waters, rich in oil and coal, sugar cane and tobacco, tin and copper, precious stones and creative spirit. Don't look for it on the map - in the meanwhile, it exists only at the atlantic_rep community (Russian, other language versions considered).
The year is presumably 1934, no exact date given. The Republic is going to celebrate its Centennial - with navy review, air parade, and every kind of festivals. Of course there are pirates, spies, at least one Mad Scientist, brave sailors and aviators, femmes fatales and lady adventurers. And lots of Dieselpunk - factories and workshops, weird airplanes, flying carriers, streamlined trains, air taxicabs, destructive secret weapons, etc. etc.
But we'll never take our Dieselpunk Legend to the extremes like this:
No flying dreadnoughts!
Anything else possible.