One of the things you can do to add that authentic old world feel to your S+ is adding a mechanical bell. In the old days, most machines used to have a bell that would ring on big payouts (big relative to years past). You can buy a bell and the associated harness for under $20 in most cases. See the picture below:

Find a place to mount the bell, in uprights it's usually behind reel #3, in slant tops is behind and to the right of the hopper. There are a couple of screws on the back that the bell neatly fits in. You then attach the harness to the 2 pin molex connector on the cable attached to the bell and run the other end of the harness to the motherboard's bell connector. Depending on what type of machine you have, the connector is labeled in the pictures below (slanttop on left, upright on the right)

After you've installed the bell, you need to configure the settings so that the bell pays on big jackpots, or any pay. Any pay can get annoying, but if you like the sound of the bell, be my guest. The bell is REALLY LOUD, so have fun and happy bell ringing. The options are found in Page 0 section 6, set to 0 for hand pays, and set to 1 for all pays