I posted this on the PCGS forum and someone suggested I post it here also. Over the last few years a number of fantasy overprints have appeared on WWII era world notes. Most of these are from Europe (German, Polish, Hungarian, etc.) None of these stamps had been seen in the previous 60 years on these or any other notes. Some of these are from German military units, some from concentration camps and other locations. Here are a few of them that have been on Ebay recently. This city of Danzig stamp on the left and the SS stamp on the right have appeared recently on many German and Polish notes. They certainly do not belong on Allied Military Currency for Italy. The seller of thiese notes identified them as German issued occupation notes. This is the back of a 2RM note from the Reichskreditkassen (Government Credit Office) also bearing a Danzig stamp. The RKK was established as the issuing authority for the occupatio notes used by the German military. RKK notes were not valid in Germany. Danzig was assumed into the Reich in 1940 and regular German paper money circulated there. RKK notes did not. RKK notes were overstamped by the Reichsbank in Schleswig-Holstein at the end of the war as emergency currency but Danzig is well outside of the area where these notes were used. This Polish note was issued in 1940 by a bank established by the Germans in Krakow. It bears a stamp purportedly applied to it by the SA of the NSDAP. The SA was the Sturmabteilung or the Brownshirts and NSDAP is the German acronym for the Nazi Party. The SA was suppressed by the SS in 1934 in a power struggle (the Night of the Long Knives) and was long out of business before this note was even issued. This is a regular 100 RM note issued by the Reichsbank used in Germany from 1924-1948. It bears a stamp from the 3rd SS Panzer Division. German military units outside of Germany were paid in RKK notes or in one of two types of military currency that bore no resemblance to regular German notes and could not be used in Germany itself. German military units inside Germany were paid with regular German currency without any distinctive identifiers. These same types of overprints have also appeared on Hungarian and Romanian notes and even on the German military notes. They have been discussed on German paper money forums and the overwhelming concensus is that they are modern fabrications. While prices were initially very strong (the underlying notes are common and do not justify a premium) they have come down considerably as word of their dubious status has spread or the makers so flooded the market that they no longer appear to be scarce items.
Seen these many times on eBay, and without any research, decided to stay away from these since they can be easily fabricated. If I wanted silly stamps with swastikas and skulls, I could have printed and ruined the notes myself, save a few bucks on eBay shipping fees. Thanks for the informative post.