Took a badly marginal gba pcb and transplanted the CPU and RAM into this new motherboard. The soldering was a nice challenge but I had an issue with the cart slot. A pin was bent, so had to fix that before games would boot. Very happy with the result. I've uploaded a picture of the back of the shell as well. https://imgur.com/a/opXFA5B
Also in person, the plastic is not cloudy at all. The motherboard is here https://funnyplaying.com/products/gba-custom-upgraded-motherboard-replacement?variant=40990162059325
Thanks! I'm actually doing my first playthrough now.