Looks nice. The only thing I'd have done differently is a custom control panel with six buttons and three button mode toggle instead of the TurboSticks.
Yup. I would have stuck a Sanwa stick in there with an orange ball-top and grabbed 6 grey Seimitsu buttons for each side. Of course, you can always do that later.
Why the LCD? I would have just made a JAMMA harness to hook that TurboDuo up to and used the original monitor that game with the cab.
All that being said, this looks like an awesome project. It would be cool to make a JAMMA cab that you could stick any of your old systems into. Wouldn't be *THAT* difficult, really...