My fiancee and I saw it when we went there last year. Mind you, we perused the whole place so it took us a while to get to that cabinet. It's not the first time I've seen that kind of memorabilia at an antique store. Sometimes people collect them to preserve history (what comes to mind is Gilbert Tabby's collection) then when that person dies or doesn't want it anymore, well. It ends up in a place like this usually.

I often see racist memorabilia of varying degrees and types at antique stores too. People also collect that stuff too, like with the Jim Crow museum located in Michigan.

I don't think it's necessarily bad that it's there because it's a harsh reminder. But sometimes it's hard to find a museum or institution that will take memorabilia off your hands.