Heh, I see all of the titles on my list except for "Cannon Fodder" from "Memories" are included in wikipedia's
list of steampunk works. I knew I should have let the internet think for me...
It's interesting that they include "Howl's Moving Castle". That came up in my reflections but I didn't include it because of its inclusion of magic into the metaphysics of the imaginary world it takes place in. To me, that makes it fantasy, whereas retro-futuristic works are only extraordinarily unlikely extrapolations of past technologies and societies. "Nausica: of the Valley of the Wind" is also included, which I didn't include because it includes an alternate evolutionary history (giant bugs and a toxin emitting jungle are everywhere).
I thought of "Spirited Away" as well (Miyazaki seems to be enamored with fantastical extrapolations of bygone technology). Look at this picture:
Here, elaborate all analog technology (in the form of thousands of card catalog-like drawers, pull levers, and cranks) is used to operate a bathhouse for spirits, but requires an extraordinary spider-like humanoid slave and enchanted soot motes to succeed. It seems to replace the steampunk aesthetic of innumerable tubes, dials and wheels organized in unknown ways, with simpler and more recognizable operational components used in magical ways. Both are appealing aesthetically, but I wonder why?
I also almost included "Dark City," but held off because its aesthetic seemed more 1940s, and that's too recent. The internet has since informed me it is an example of "Diesel Punk". Apparently "Sky Captain and the World of Tomorrow" is
of that genre too...