I know this is a little late, but the thread caught my attention since I am from Tulsa as well. I'm jealous, I've never been inside. The collection is called the Stokely Event Center and is used to host wedding receptions, corporate parties, etc. Stokely is a Tulsa company that does billboards, so it fits with their area of business. So really, anybody can get in to see it, but you might have to plan a wedding to do it!

http://www.stokelyeventcenter.com/