I've been thinking about picking up an old project of mine. The idea is to "modernize" a GBA SP, and by that I mean a custom shell, a larger battery, stereo speakers, and a Micro USB/USB C charging port instead of the old proprietary one. Maybe even a headphone jack.
The project fell through because the broken AGS-101 Gameboy I bought from eBay was lost during shipping (and my 45$ along with it ).