Rampart 3 player trackball PCB on a supergun

[Battlesmurf]

SO, dumb question (and complete SG noobie lately). What's the best way to play 3 player trackball rampart on a supergun? I have the full panel, jamma board, and harness for rampart. I'd rather not hack apart the harness, so ideally I guess I'm looking for an adapter to use with the game. Is anybody aware of such a thing- can anybody build one for me?

Thanks!