Supergun help needed

[Cobra Kai]

A friend died in the past year, and his wife has graciously allowed me to kind of clear out some of his video game stuff, and she let me take this supergun and two joysticks, plus a Primal Rage pcb. I told her I would test it out and see if it all works, then we could work out a deal for the rest of the pcbs.

 

I don't really want the stuff, but it is interesting, and it is probably valuable. I have some pictures. I hooked up some AV cables, plugged the big blue connector to the Primal Rage board. That seemed easy enough. After turning the power on, I got a video feed to the TV, but it was very washed out in pink and purple hues, in different bands. Also, there was not any audio. There is another little connector coming out of the supergun, with yellow and black wires, which I couldn't figure out what it plugged into. I'm assuming it has something to do with the audio, and perhaps fix the color issues? Anyway here's the pictures:

 

 

 

 

What do I plug that other cable into? Also, what kind of value am I looking at here?

[ProperRogue]

I'm not sure if it helps any, and I really don't have any experience or knowledge of my own about the Supergun, but I do know that AssemblerGames has an area of their forum dedicated exclusively to the Supergun.