Back in middle school I read a wonderful book called "Band of Brothers". It was about USA soldiers fighting Nazis and finally looting Hitler's compounds for loot and keepsakes. While I was reading the book I wanted to be there taking part in stealing stuff from the most evil people that ever lived. If you are looking for some WW2 German stuff I have bad news. Some fakes are indistinguishable from originals. But Here are some places you can start.
Join this forum
https://www.wehrmacht-awards.com/ and ask them around. Learn from the community
After you learned how to tell from fakes you can try to source items from these following cites.
This is a good source
ONE MORE THING
In USA you can legally buy any firearm. One thing that Chinese and Polish fakes cant copy is functional firearms. You are pretty much guaranteed a real WW2 And functional Luger if you buy it in USA.