Depends what they mean by "Nazi memorabilia." During the Nazi era, the swastika was on everything. Coins, stamps, bank notes. Probably on many everyday items. Which meant that everyone used "Nazi memorabilia," even if they opposed the Nazis.
They stamped everything they made in the late 30’s through the end of the war.
They built a bunch of compressed gas cylinders like what you would see at a welding supply that were sold over here. If you look at the necks of them you will see a diamond made up of 4 squares. When the cylinders were sent in for their 5 or 10 year hydro test, they were re-stamped to get rid of the nazi symbol. Rarely you might find one that got missed.