My switchbox was on the porch when I got home from school last night, so I eagerly opened it up and pulled out the multimeter to make sure it was straight through for all pins (I know some of them only send 14 pins through). To my joy, it was straight through. Well, it was 24 pins straight through (the 25th pin was a shared ground), but I’ll take it. In my pinout the 25th pin is for the home button, but since only the 360 and PS3 use a home button, I only had to move that pin on those two project boxes. I snipped off the shared ground wires.
I opened it up to see if it’d be possible to gut it and put it in my stick, and happily saw that it was. The selector knob is part of what looks like a turbine that has columns of three wires coming off of it all the way around. The wires are all going off to three different female DB25 connectors (one for the input, and the other two for the A/B connectors), and the turbine/knob and connectors can all easily be removed from the box. I took my stick’s signal/joystick wires, removed them from the barrier strip, and then clipped off the input DB25’s wires, one at a time, and spliced to the stick’s wires to match my pinout. When that was done, I spliced the B connector’s wires to lengthen them (they’re fairly short out of the box) and screwed it into my stick as the project box port. Today I’m going to send the A connector’s wires to a terminal strip, which will feed the internal PCBs.
I’ll take pictures as soon as I can and post them in the project box thread, but to answer your question, yes, you can do this. Here’s the exact box I ordered (it came to $13 with shipping and arrived about a week after I ordered it):