I might…
Planning on posting them over time on !gameart@sopuli.xyz, and here, too.
You can find them as a bonus download on GOG. They are extremely highres, I reduced this one to a quarter res. The original file is a single page pdf of over 100 megs.
You could. The original file is print quality.
You can find a 1.3GB download of posters in the extras on GOG.