Aramark is licensed for a repeater on 463.2250, and simplex on 457.1875 (license WQAW769). They probably provide the food service there, so that's probably not exactly what you're looking for. Also check WPSI591, which is licensed to HCT Convention Service Contractors.
I go for the Antique show, among other shows. Usually the security is outside, so I just did a search of the 450-470 bands. I might head down for the antique car show also! This sounds like a job for Signal Stalker or Close Call!
Yup I plan to take the 246T down with me like I always do! Hope to get some good hits like I did last time! Dave let me know what days you're going, maybe we can have an eyeball?