I don’t know if there are many original “Confederate” flags left, but I doubt it’s many. As to Nazi flags being sold at gun show, that could be different. American soldiers in WWII brought a tremendous number of them home from the war, as well as a lot of Japanese flags, Japanese swords, German Lugers, arm bands, even automatic weapons. (Luger pistols were a real favorite, but hard to come by. Flags and arm bands were a dime a dozen) A lot of gun show people are collectors of various sorts. I don’t know about the Confederate flags, but I would fully expect to see some original Nazi flags, arm bands, Japanese swords, German Lugers and Japanese flags. Rising Sun flags were also very popular because a lot of them were made of silk, so they could be stored in tiny spaces and last more or less forever.