The third knife in photo 6, the double-edged dagger, looks amazingly like a Sykes-Fairbairn commando dagger of WWII, right down to the solid-metal handle. Some classic designs just keep coming back century after century. I'd read much of this material in other articles about Argentine knives, but not in such detail, concentrated in one place, and by a scholar who knows his Bowies as well. When I started college in the mid-60s at the University of New Mexico, the library had a little book called "Esgrimas Criollas," about Argentine knife fighting and duels. When I was back in college after returning from Vietnam I found that it had disappeared, and years later learned that it is a quite rare and collectible book. I wish I'd stolen it when I had the chance.