Here's the thing, your wife likes the SS, so if you get rid of that, you risk losing a degree of her support of your nutty pinball hobby. You don't want that. You have only one more option. You find a way to make room for a 5th pin and you justify it to the wife by saying that your ONLY option was to sell the SS, but you know how much it means to her, so you just couldn't do it! You'd never sell her baby! What a great guy you are!
You are now a hero. Congrats!