If part acquisition is on your mind,
There is a mustang specific parts shack In Edwardsville, IL called the Mustang Corral. This would be about a 10-15 minute venture from the St. Louis downtown area. They seem very knowledgeable and have a good number of hard to find bits and pieces. Their number is (618) 656-5428. It is the opposite of flashy, so don't trek out there if you’re looking for neon or presentation of any kind. But it you need vintage parts; these boys can usually walk right out to one of their shelves and pull just what you need. I'd bet at least 50% of my car (by weight) came through their shop. If you aren't planning on having a vehicle with you, it would be an expensive cab ride; I'd rethink this particular stop. If you'll have wheels, and need parts, they're a worthy stop. Let me know if you need more info... (I don't work for them, or with them etc... I just seem to give them my money, frequently.)