As a collector of military items, in some ways I agree with you all, and then I don't to be short on that sentence.
I must say that this is the second one this year that I have stopped, told a few vendors that some of the inert ordnance items they have displayed are not true "INERT". I also stopped at one table this past weekend and was talking to the old man, he looked at me in a nasty way. As I was talking to him about items he had out, he was surprised that I was pointing out the names of the items, the country from which it was first used and so on. He once again spoke and this time with the words "you know your shit, I am surprised, here is my card which I do not hand out much".
As for the KKK stuff, I walk right past the table. There might be another item I would buy, but since they are displaying that out, off I go. They should really have that out of view, if someone is looking for it, they can ask the vendor.
And here I go now into the "NAZI" subject.. When I am at a show, I will ask when looking at German gun's if the "Chicken Mark" is on the gun. I have respect for others that are around me and will not use the word NAZI.
I am a huge military collector as some of you know, my items in my collection including firearms range from CW,WW1, WW2, (both axis and allies) Korea, VN, and so forth. There was a time in my collecting that I had items displayed in glass cases, that was up to the time one of my daughters asked about it. I took the items down, that was the last thing I did not want is her in school and saying to the teacher that "my daddy has that on the walls" after looking at a world history book.
I'll admit that in my living room I have a 1/4 mannequin with a USGI Kevlar helmet and NBC hood and mask on that is atop of my desk. Why? Because I can. (well the wife hates it.. but)