First of all, to the O.P.
I hear you. Here's hoping the gun shows are still around when my kid (4y.o.) is old enough to know whats they are. He's been to one, but was in a stroller and slept through it. I remember the good times I had with my Dad hunting, fishing and shooting (and oggling the goods at shows). I hope to have some of those same experiences with my son.
Now the Confederate battle flag. I've never seen one at a gunshow. I've seen the red, white and blue flag, but not the battle flag. I have one and fly it once a year. It's an artifact of history, not a symbol of bigotry. Suppressing history is bigotry. It happened. A lot of bad stuff happened in human history. Learn from it and move on.
The swastika has been around for over 3,000 years that we know of, maybe more. It was found in lots of early American folk art and was an accepted good luck symbol. It was and is an Indian (not Native American) good luck sign. Buddhist prayer symbol. Found in Egyptian tombs. The fact that it was copped by the nazis casts a pall on it, but seeing it on non-nazi stuff shouldn't give you the heebie-jeebies. My Aunt Sandy has antique quilts with swastikas on them. American origin and predating WWII by about a hundred years. They do not, however, have goose-stepping, armband wearing, genocidal maniacs on them.
There's a difference between the seller of relics and war trophies and the skinhead dressed up in it.
If nobody re-enacted the axis, what would WWII re-enactors do? That's like a Civil War re-enactment were everyone wears blue (or gray) and stands on the same side of the field.
So here's to the gunshows. Some are good, some are not so good. Some are downright lousy with nothing but beef jerky and one old guy with a broken shotgun. But they're still gunshows and we need to protect the right to have them.