You would wind up with three sounds. One for each of the chimes. Maybe six if pairs play together and you can decode it.

Actually, Strikes and Spares has four chimes.

Because the chimes are driven by solenoid driver board pulling the coil output to ground, connecting a logic level sound board is quite simple, just connect the sound board ground to game ground, and connect the chime outputs to sound board inputs, leaving the +43V coil common wire disconnected. Maybe you need pullup resistors at the sound board inputs, to +5V or whatever the sound board voltage is.

The (+) wires are all connected together and that goes to +43V. Do not connect that to soundboard.
The (-) wires are pulled to ground when MPU wants the chime to operate. So you should have an active-low input on the mp3 board.

The board looks very suitable. Connect the sound board "GND" to game ground (NOT to +43V!!!). The chime wires go directly to K1-K4, no extra resistors needed. Disconnect the wires from chime, do not leave the coils connected.

For the 9-24VDC input, I recommend you use a separate small power supply for better quality.

Yes the +43V is not needed. Good luck with the project!

just quick warning to make sure to the input signal wires are disconnect the coils. 43v will feed through the low ohm coil winding and may blow up inputs on your sound card.

Cool project, let us know how it turns out!

MP3 vs wav is just format. Should not matter.

You probably do want one that can play multiple sound calls on top of each other. I forget the terminology used.... Number of voices or channels at once or something like that description. Same thing like in keyboards, how many sounds on top of each other it can do.