The Gamblers general Store in Las Vegas is a great place to start looking. They know the laws for each state, and will ship your prize home too.
I agree with Ralph, the real old slots are very expencive. We looked into buying one a few years back. About the years that get a lot cheaper, PA laws restrict ownership, so we never got one.
Now I'm not recomending you do this...but, check neighboring states ownership laws, and have a freind in that state take delivery. Then drive and fetch it. As long as it's for personal use, the worst that happens in PA if they somehow find out is, they will take it as contraband. If you really want one that bad, it's a thought.