Ah, apologies.
The three contacts are ground (the one on the side), normally open and normally closed.
Most arcade coin mechs/buttons/joysticks etc use the normally open contact as when the button etc is pressed the circuit is completed.
Daisy chain both of the micro switches grounds and connect them to one of the ground terminals on the IPAC. Then connect a wire to each of the normally open terminals on the micro switches (dont daisy chain them) and run the separate wires to the Coin 1 and Coin 2 terminals on the IPAC.