Five Unmarked Pocket Knives

I look at five unmarked knives in my collection. All are excellent knives, in my opinion, but as they lack tang stamps or any identifying marks are they worth having in a collection? It all depends on your own point of view? Are you collecting for value or are you collecting what you like? That's the question only you can answer. And just where in Germany is the town of "Inox" and when did the "Rost Frei" factory make knives!