I have one from an old tekken 4 conversion I parted out...but it already has 4 button holes + 1p/2p start + joystick holes drilled in it....also whoever drilled the button holes got them a bit crooked...anyways, if you're interested let me know and I'll dig it out and post a pic for ya.
Oh yeah, it still has the overlay from t4 on it too so you would probably want to peel that off.