I've been working underground for quite some time on some of these modifications, and there has been a pretty good demand for them. I put this site together: http://www.mashmods.com for anyone that's interested. I also recently added the GP32 joystick/button modification, which is a solution for people with non-responsive/loose joysticks and inconsistent buttons. Please take a look if you have time:
http://www.mashmods.com
http://www.mashmods.com