You cannot carry a loaded firearm into the show.
They let you buy firearms inside the show.
They let you buy ammunition inside the show.
They do not check the status/condition of firearms you carry out of the show.
Just remember there are "eyes in the sky" all over the place.
There have been enough (being defined as more than 1) incidents of someone discharging a firearm inside the show that the folks running the show do not want to deal with the aftermath again. Nor does RIR. Nor the Henrico PD (well, they do hate doing the paperwork.) The "our insurance requires this" line may or may not be true - I just don't see that it matters (their place, their rules, you agreed to them when you bought your ticket).
See the several magazine vendors - they have mags for guns that no longer exist, as well as some for guns that have not yet been invented.
You might have better luck with the on-line sites for finding that Colt. But half the fun of a gun show is wandering the aisles trying to figure out how close you can get to what you want before you start thinking about compromising. The other half of the fun at gun shows is people-watching. (The People of Wal-Mart buy guns.)
Stop by the VCDL table and chat while you complete your membership application form.