Even if he did write it, how much effort does it take to leave these traces behind? Is there a reliable way to link these traces to other, known materials to ve

Even if he did write it, how much effort does it take to leave these traces behind? Is there a reliable way to link these traces to other, known materials to verify they came from Vlad? Can it at least determine age? Or could these traces be from any person who handled the letter at any point in history?