The standard AS-02 cable will work on all machines that have normal stop boards (newer NET machines do not), but it does not have the credit-add feature.
If your model is not yet listed on the Credit Table, the best way to identify the correct coin sensor wires to tap into is to have access to a voltmeter and measure the voltage on the sensors at the connector. I recommend removing the coin mechanism from your machine, leaving the wires attached. Then slowly pass a token past the sensors while measuring voltages. You should be able to find the wires that change voltage as the token passes. (You will most likely generate coin errors while doing this.) Most machines also have LEDs that will flash as the token passes by which may aid in this process. As shown in the picture below, a good point for your negative voltmeter lead to get the 0 volt reference is on the left lead of the C6 capacitor.
If the coin wires are 5V and go to 0V when the token passes, it would use the AS-02C or AS-04 or AS-03-NO. If a higher voltage, but still normally high, you would use the AS-03-NO or AS-04. If the coin sensors are normally low and go high when the token passes, you would need the AS-03
For example, on a Sammy machine, Pin 2 (yellow) on the coin mechanism wires to pin 2 on the microcontroller (wire "B") and Pin 5 (white) on the coin mechanism wires to pin 3 on the microcontroller (wire "A"). (My Sammy Aladdin machine uses 12 volts on the coin sensors so you have to use the AS-04 cable.) You will need to tap into the existing wires, using the supplied quick T-Taps and Spade terminals.
