Bare Knuckle Boxers - Concept Art

Your poses are a more modern fighting stance. The bare-knuckled boxers tended to have their wrists turned, as if preparing to deliver an uppercut -- their forward one, at least.

[Aside: There's actually a good reason for this. In bare-knuckled fighting, the body is a better target than the head, because you're too likely to break your hand on somebody's head. Also, a punch to the stomach with a bare fist is far more damaging than one with gloves on. Having the forward arm with the wrist turned as for an uppercut means that the elbow does a lot more for protecting the body than in the modern stance. Try it yourself and see how the elbow moves across when you turn the wrist.]

Also, I believe that wrapping the fist in tape was only a brief thing, and was quickly superseded by actual gloves. For the bulk of the bare-knuckled era, they were actually bare knuckled. (I'm not sure about this.)

Some suggestions for characters:
Gap-toothed grin
Tattoos, especially an anchor or crossed swords.
Cauliflower ear and/or nose