My Pop'n Music Playstation controller

I was in Japan in January and bought a bunch of stuff from Book Off/Hard Off (which I highly recommend; Hard off is your dream place ). I got a half-dozen Pop'n Music games and a Japan-region PlayStation 2. I also got an official Pop'n Music controller. It isn't very good (rubber dome switches and is much smaller than the arcade), so I decided to build my own arcade-style controller (for which…