First, welcome to the forums. There is a wealth of knowledge here and then there is me! I don' think there are any true Nazi folding knives. Read this link. About 2/3rds of the way down the page is a good explanation.
Jewelerguy has it right. Fantasy item from the 1870s-1980s. There were no pocket knives made during the Hitler era with his name or likeness on them, any you see are modrn fantasy pieces. He is correct about the KKK knives, every one is a fake or fantasy item.
Jewelerguy, check out my recent posts of some forged sterling bracelets and a couple necklaces I just made, what do you make?