Unless I'm missing something, it's doubtful that you'd have found yourself in any trouble. Only citizens of the GDR / East Germany wouldn't have been able to bo

Unless I'm missing something, it's doubtful that you'd have found yourself in any trouble. Only citizens of the GDR / East Germany wouldn't have been able to board that train. Since you were a visitor, it shouldn't have been any problem assuming you had proper identification/papers.