James,
the difference between BL and Frazier appears to be more than one step as Alan observed.

Also, on your Altgens view.
You have Lovelady coming down to meet his position for Ike's photo but that doesn't appear correct.
His position in Altgens is the highest we see him and he's in the that same position in Wiegman IMO because we still see a slight leaning, then it's from from that position he goes down to a lower step.