My opinion: if you're a real collector, particularly if you already own the genuine articles that you bought during the war, then you can tell if these are fakes.
If not, you should contact a reputable expert/experienced person who deals in these types of memorabilia.
From my experience, once a person in those countries makes a profit selling a genuine sample, suddenly a thousand knock-offs spring up looking to make maoney.
I experienced this in S. Korea. A friend had a flower tattoo on her ankle. She went to an artist and asked for a painting of the tattoo design. After a week, he finished, and she was really happy with it. Good quality work.
Two months later, when we had returned to Hawaii and then back to S. Korea, we went window shopping. Lo and behold, no fewer than 4 shops had that painting in their window for sale!!
Goes to show, when there's a perceived demand, supply will follow.
