Jack_White_35mm_slide.
Thanks for posting all your pictures and great information! I am a researcher too - just trying to dig out the truth and make sense of it. If I see evidence contrary to my theory, I have no problem changing my theory! I will admit sometimes my imaginations gets fairly vivid with possible scenarios!
It looks like the bottom image is a blow up of Zapruder Z316? Z315 also shows start of deformation process above the top of head and Z316 is a completion of it or extended outward! It appears to me that seeing more in Z316 than Z315 suggests an outward push coming from lower front and the possibility of a 2nd shot from front. With your better pictures, I can also now understand the vertical line on Z337 in front of his ear with all skin hanging including bone material still attached to it.
The whole front you see in all the images must include a good portion of face skin ripped off and hanging down? Maybe the first bullet sheared the scalp? When the head moves back and to the left with the 2nd shot, the entire hanging portion of skin/bone flips back so as to make the skin come back into position. In Z321/Z322 the head appears "shorter" in Zapruder frames. But what kind of shot can rip/tear skin off like that other than a glancing blow? Then, when the brakes are applied and the head rotates forward, the skin flap flies into a new position and pieces drop out at Z334/Z335 into his lap. That damage could also be from a Z315 penetration!
The more I look at it, the more I think there were multiple shots - almost simultaneously. That however is like having nuclear clock timing! If he gets hit initially at Z313 and then another comes in from say the gutter drain (down and front)......(Z315/Z316), that is only 1/8 of a second later and would be freaky perfect timing on a moving object! It passes almost through the existing open wound/fractured skull and comes out more to the top LHS of his head! It is the only theory I can come up with so far. A Z315/16or17 shot also matches what you see on the Moorman polaroid.
On an aside note, I had watched a documentary a few years ago claiming a gutter drain shot. The passage way is big enough for someone to stand in they claimed! That does make sense as drainage gets bigger as you get closer to its drain port by a river. That could match a second shot position! (Z315 and Z316 in progression).
The purple rectangular image you see in your post #15 would be the second shot entering an already fractured skull and exiting out in the green portion. To me, both anomalies in the cracks are a bit unusual artifacts. If that image is real, that is a very plausible explanation IMO. That entrance anomaly (purple rectangle) does look like a second shot! I have seen skull shots on game animals with "normal bullets" and you only see the penetration hole, no skull cracking in direct hits. Bullets generally lodge in the animal's head and doesn't have enough power to go through the thick skull and out the other side! Here the skull opened up, which then allows another bullet enough momentum to pass through to the other side and out! An hypothesis! I found a big game animal skull like that with only a small entrance hole on the prairie this last fall (no cracks) - obviously a hunter left it or landowner put it down and left the animal there years ago. In the case of JFK, I would expect the bullet should be laying there somewhere in the grass and could still be found (Z316).