My next project is obvious then: inspect my cables and the JPAC and manually wire the 3 player select buttons to the JPAC so I can either use them as a third button OR to select players.
Is there a switch on the JPAC for a coin switch? I am guessing there is. I need to look and see how this works. I see the switches are labeled like switch 1 switch 2 on the JPAC but not sure which ones to use. I am guessing I can find that out my looking for a diagram on the site though.