While I was making my 2nd controller mod I had an accident involving getting some super glue on the circuit board pads for the buttons, which made them very unresponsive. So I ordered a new controller, and put it aside for a later project. This weekend the parts came in and I set to work, to use the circuit board for a fighting controller/retro gaming controller. So I built the box out of mdf, painted it, wired up the buttons, the stick (had to modify the sanwa stick as I wanted it to work on the analog left thumbstick to allow it to work as a xbox 360 controller as well), removed the right stick and put it on a circuit board and mounted it on some distances to get it at the correct height above the main stick. I then found some suitable battery clamps that could hold the rumbler motors and hotglued them to the inside of the box, which resulted in the whole box vibrating when playing a game that supports rumbling (street fighter IV, but sadly not Super Street fighter iv).
Just throwing up the video here so that someone else might find the inspiration in case they have an extra controller and want something that works for mame, retrogaming, fighting games, and even as a regular controller (for some games). The right trigger has a full engaged and 1/2 engaged button (two buttons) to allow it to be used in some game that rely on that function. If anyone have any questions about how to do this build, feel free to ask
My Fighting Stick - 3rd Xbox 360 controller mod