Got it working.
Randy, I know you don't like suggestions too much, but considering I spent about an hour on your site trying to ident this board before I asked here, it might be a good idea to update the picture on your site. There is a fair bit of difference between the one I have, and the one shown. Considering you sell more than one board, it it a little confusing.
Also, a little more elaboration in the instructions noting that it is a gamepad, and might have to be calibrated, would be handy. The page and a half of docs, honestly, were just the led-wiz docs with a small mention that the /GP will show up as an 'HID device' (which is sort of incorrect as it does show up as a game controller, as you said).
Just a thought. It's still a neat solution for a simple mame setup with lighting.