James,
Billy's big lean in Altgens is to his left, not forward(did you say, you had trouble replicating that in your models? If so don't worry).
Anyway, his legs would not be and are not visible from Ike's position(but again no big).
Regarding the possible morth.
Altgens to Wstep6 was what I was requesting because I don't see the difference in Lovelady and Shelly in W1 and Altgens,
that is, it looks about the same to me, can you persuade me otherwise?
Also for Alan's benefit, perhaps you should do a close up of BL's and BWF's heads in the images and your model so we can see what the difference/trouble is.
I was looking at PMvBL in your latest post and they seem to line up with Wiegman only when Lovelady is about to hit the 6th step,
if you brought BWF forward in that frame that might be a match all around(I'm restricted to plain eyeballing it atm, don't expect any sudden overlays).