I'm surprised you don't just march up to some unsuspecting Norwegian and yank the sweater off his back.
You know, I had not really considered that as an appropriate way to get this sweater. As Anschluss is a well established German tradition- and threatening others and intimidating them to give up land, money, and goods has been particularly lucrative, it stands to reason that idea should not be overlooked. Anything gained by force or threat should be considered to be "fair game" and culturally appropriate to display (or, in this case, wear.)