John Clements

I could not find any clip of him sword and dagger. And it's relationship to boxing of another era.
But I did find this clip and perhaps one can see. Obviously the distance will be much closer. Things will have to be altered. Things will be deleted. Ideas from more modern variants of fencing will show up. Other methods will be used. It will not solely come from this but this would be one of the cores during that era. It was not the only "style" used to box with when it was being employed. There were other concurrent lineages. Each would take from the other. Grappling still played a part. As did kicking if the rules allowed for it.

Sword and dagger sparring-
https://www.youtube.com/watch?v=3u9al15uHt4

John Clements empty hand vs. knife. Some may see things very similar to what you may do in your art.
https://www.youtube.com/watch?v=xayU3xuObDo

John Clements talking more on long battlefield swords. Notice the footwork and body movement he races through during discussion It shows up in boxing to this day. Often in shorter steps.
https://www.youtube.com/watch?v=ov_iVrHy4_A

Mr. Clements shows in the knife defense video five basic techniques with follow ups. All seem strangely familiar to me (especially no 4). ;)
1. arms form rectangle in front of torso (outside)
2. double handed block downward
3. arms form rectangle (inside)
4. one fist up, one down, then switch
5. downward palm heel strike
Since all these are reconstructed from old combat manuals, it would be nice to know his sources. They may have influenced Escrima.

I think his demonstration has some weak points though.
* Isolated movements without partner differ somewhat from their application.
* Techniques are displayed at 80% speed.
* The inside of his wrist is turned towards the blade. I'm by no means an expert, but that seems like a recipe for disaster.