Many years ago there was an American that sold Nazi stuff from the U.S. and the Germans didn’t like it because some Germans were buying through the mail, the guy went on a trip to somewhere like Holland and the Germans nabbed him, and took him to Germany to face charges.
I never saw what became of him.
Are you really sure? That would have been interfering with the criminal justice system of the Netherlands. This would, most likely, have caused a terrible scandal with strong international repercussions and huge damage to many international relationships, I bet.
Furthermore, I recently read an article on the subject of Nazi devotionalia. It is legal to own them and to have them in your house, if you have inherited them from your Family.
Still, it is discouraged to deal with them in a business-like manner (though in fact, prosecutors would have a very hard time ascertaining the provenance of any given item from the NS era). Nonetheless, there was a huge auction of NS paraphernalia in 2019, in Munich, which was widely criticized.