What I did there was grab the Black Man's left elbow from the Wiegman film. That's all that would have been visible to Altgens. But, it must have exposed something that they didn't want seen, such as Oswald's right arm coming down to meet his left in the hand-clasping. So, they needed to cover it up, so they decided to completely revamp the Black Man. So, they took the profile view of him from Willis and plopped it in there. Then, they came up with the shamrock to place below, to represent his body. And that turned it into this:
You can call it a hypothesis, if you like, but let's be clear about something: the presumption that the Black Man should look the same in Altgens as he does in Wiegman is NOT farfetched. In fact, it is the default. The burden is on others to justify why he should look any different, considering the proximity in time. The concordance in time between the Altgens photo and the start of the Wiegman film (as seen today) is so close that it's hard to say which came first, and I've seen it argued both ways. The most the difference could have been is a full second. Are we to assume that Black Man turned, not just his head, but his whole massive body in that amount of time? And then back? Why? Why should we assume it? Because of the photo? But, the photo is in question. The photo is in dispute. So, you can't use it to justify anything. Hypothetical or not, what I am suggesting is the most likely thing, the most plausible thing, the most reasonable thing.
And then when you consider that the disputed image happens to match perfectly another image taken by another photographer from a completely different angle at a different time? And yet they look the same?
"I, like God, do not play with dice and do not believe in coincidences." V in V for Vendetta.