Jim, I think you hit the nail on the head regarding the Pandours and the curious notch on the sword. Franziskus Freiherr von der Trenck must have been a remarkable man. I read what purports to be his auto-biography (some argue it’s a forgery) which is a highly entertaining and in some parts little sad story:
Memoirs of the Life of the illustrious Francis Baron Trenck, Sometime Lord of the lBed- Chamber to her Majesty the Queen of Hungary and Bohemia. And Colonel of a Body of Pandours, and Sclavonian Hussars. Containing A compleat Account of his several Campaigns in Muscovy, Silesia, Austria, Bavaria and other Parts of the Empire, Together with Divers entertaining Anecdotes relating to his secret History. Written by himself, and done from the original German into English. London: printed for W. Owen, 1747. There are persistent rumours he had an affair with the Austrian empress which may at some time have turned sour and allowed his enemies to conspire to have him imprisoned. In addition, this report may also be of some interest:
http://www.etd.ceu.edu/2015/balic_juraj.pdf.