I had bought a USB-C power module for the Wonderswan Color from Retro Game Repair Shop, but it's a bare board so I wanted an enclosure so that it wasn't exposed
https://retrogamerepairshop.com/collections/wonderswan-color/products/wonderswan-color-usb-c-power-module?variant=40026885849260
The author marked this model as their own original creation.