One step closer. Still need to replace the psp joystick with a genuine one and wire it up, but it's all together and working pretty well so far! Got the 3d printed back case on for now as it allows a little bit of flex, but I'll sort out some extra clearance on the aluminium version in the next few days. Still want to make new buttons out of aluminium, but the plastic ones will do for a test. Seems to run some N64 and PlayStation 1. Haven't loaded too much up onto it to test but hopefully I'll have a bit of time tonight.