I love the Tournament Start feature on the new Sterns and it is a shame that the button does not at least come on the new LE's and Premium. Fortunately it's not a difficult thing to hook up. The wires are coiled inside the cabinet near the buttons. There are two types of Tournament buttons that I have found. BAA sells a more expensive one ($13) with lugs on it that the existing wires can connect to directly (although you will need to connect the diode inline). The BAA Tournament button uses a #555 bulb. PBL sells a cheaper unit ($5) that has solder lugs on it like normal switches and sockets have. The PBL unit uses a #86 bulb. In either case you MUST replace the bulb with an LED if you are using it in an LE or Premium.
I used the PBL switch and soldered some 20 awg wires directly to it and ran them to a molex connector. I then cut the lugs off the existing wires in the cabinet and ran them to the other side of the molex, so the button can be disconnected.
Attached is the circuit from the manual and a diagram of what it translates to when hooking up the diode, switch and socket. If you look closely at the switch you can see the "C", "NC" and "NO' labels imprinted. If the LED does not light, it is probably just in backwards... The diode is a 1N4004 and connects between the "C" and "NC" terminals on the switch (banded side to the "C". If you are using the BAA style switch you can put the diode inline with the tan-violet wire connected to the non-banded side and the banded side connected to the "C" on the switch (no connection to the "NC" in this case). Use some tubing to cover the leads on the diode so it won't get shorted.