You're not answering the question Allan.
JFK's "back and to the left" movement clearly suggests to anyone who sees the Z-film that there is a shot from the front.
Why alter the Z-film if you can't alter that?
What's the point?
Sorry. Maybe, I should clarify. If there was even more proof of a frontal shot, you need to hide that evidence if there was even another shot. (2 shots in quick succession stated by many witnesses). If what you are saying is true, then why not investigate to prove - no contrary testimony presented at WC - case closed. We had ample witnesses that said the shots came from the grassy knoll - why was there voices unheard? Is any of that in the WC report? The investigators went to great lengths to prove that it was a LNer and that alone. "Expert" scientists said that the head moved slightly forward in Z313 and they ran with that as the ultimate explanation. We could say the President was actually shot by autopsy. No physical evidence presented such as x-rays. They didn't use them in WC report. We really don't need to see Z313 at all. Why even present any photos? They could have used all kinds of physical evidence at the scene (car, windshield etc.) The only physical evidence was a gun, casings, pristine bullet on a stretcher and a dead LHO at the hands of a nightclub owner.
Besides, You also have to make sure there is congruency between all pictures and films. You will note that there is not one film taken from or a clear view of the front of the car, all evidence presented was from one side only, far away. No photographers captured the front scene of the car or even another perspective from the grassy knoll for that matter - only Zapruder. If I brought a camera to the scene, I think I would have liked to be elevated on grassy knoll, facing the President's side and with elevation. There was lots of room over there too! Note the polaroid picture was snapped just beyond Z315 and not seen in Zapruder images. If I was taking a casual picture, I would have taken the picture a little closer to me like at Z300 where President and first lady would be facing me. It would have been photogenic and something to remember. Not one picture from that side! The polaroid was a freak picture and highly unusual as to when it was snapped IMO.