de Bacon and FitzRalph appear to be rondels only for the shoulders. d'Abernoun is harder to tell, because it looks like he has a rondel on his shoulder (since what is there is drawn in the identical style to his elbow rondel), but the line is cut off by what looks like a continuation of the edge of his surcoat, which doesn't really make sense. I feel like if he's got rondels on the shoulder he probably doesn't have a shoulder cop too, but I can't prove that.
Joe's new arms are inspired by FitzRalph. I'm not sure what they used to arrive at desgn for the termination of the rerebrace, but I'm not sure there's anything definitive to guide you other than speculation on that.
As far as more videos go, yes I'd like to. I haven't really sat down and brainstormed ideas yet though.