Check out the popular images of chokki motobu and shigeru nakumura in there "guard stance" in mark bishops - okinawan karate teachers, styles, and secret techniques. You may notice that is is pretty much identical to one of the most effective barek knuckle boxing guards. Ive recently seen several versions of Tomari Seisan from Okinawan Kenpo, each one used a slightly different height and angle for there guard most likely for comfort the same reason you see SLIGHT differences between motobu and nakumura, same reason there was slight differences in the old bareknuckle boxers but all relatively the same exact guard.
This guard is nothing new to me as the techique can be found in pinan katas, passai, and many other modern katas (usually this is a "reinforced block"
But what caught my eyes, is the highly effective "Drop Step Punch" (used very naturally and with ease by the old time bareknuckle boxers) is in this kata, and its identical to the way my grandfather showed my father, and he showed me.
Anyone eager enough could even look at the bareknuckle boxing takedowns and throws that "used to be" , take away the opponent and practice them "shadow boxing" and you will notice practically identical hand arm and leg movements found in kata ..