I moved from Austin, Texas to Jackson, Wyoming. In both places the gun clientele seems very distributed along the political spectrum. In Wyoming you need a high caliber weapon if you want to enjoy a nature hike because here nature is very keen on killing you. Austin is still Texas and Texas has a unique ability to infect people with an acceptance, if not love, for beer, barbecue, tacos and guns.
I mean, duh, but let’s be honest here man there’s like 2 and a half reasons to buy “nazi branded merchandise”
You are a giant history buff, historian, etc, and you simply collect artifacts from that period. If you are this, you probably aren’t picking random things from your local gun store, but maybe you are.
You are a nazi
You are a “history buff” that, for some reason, only collects nazi memorabilia.
Now, I’m sure some history buffs go to gun stores for that kind of thing. But let’s imagine the broad spectrum of gun store clientele.
War trophies are really common for gun shops/shows, due to the proximity between gun culture and professional soldiers (who actually collected the trophies). You focus on Nazi, and it's certainly true there are an abundance due to the scale of the conflict, but you can also find Imperial Japanese trophies and other random things some times.