Amazing work! I modded my iCade with Sanwa stick and buttons years ago (photos on Flickr somewhere) but have had the iCade in storage for years since, so I might attempt this mod in the new year! Two points (kind-of connected); did you consider the possibility of orientating the screen in portrait (tate), and what about buttons on the side (mainly to play pinball games)? I can see in the current design the speakers prevent orientating the screen vertically, but I know the original iCade design allowed for both yoko and tate orientation (as there was no bracket, so it was easy). Regarding the side buttons; space looks a little tight on the left side (looking at the iCade from the front), but could probably work if the button sat back far enough from the front and/or you routed the cable from the front far-left button differently. Anyway, nothing above is a criticism. This is fantastic, and thanks for doing it!
Rotating the screen would be difficult, because the space between the speakers and the controller is smaller than the diagonal of the screen, so you won't be able to rotate it. I've tried while design it and the only solution would involved to cut the controller box to have enough space. The OSD allow to rotate the screen so I went for that instead. I have other ideas for this iCade already on the move though...
