The conference is coming fast, and it's not a secret anymore, so I took the liberty of publishing all my design files for that version of PewPew at https://github.com/pewpew-game/hardware-europython2019

Electrically it's identical to the 10.3 verson of PewPew Standalone. Mechanically it's similar to the 10.4, except for the smaller switch moved to the upper edge, and USB port moved to the upper edge as well. Well, and the LED and button colors, of course.