Now, here's something interesting. Robin Unger says that the Muchmore frame that I picked that corresponds with Moorman is Muchmore38, which is 4 frames before the fatal head shot.
Well, I wasn't thinking about it at the time, but the Zapruder frame that I concluded must correspond to the Moorman photo is Z-309. And that too is 4 frames before the fatal head shot.
I love it when everything works out.