I see your first witness is high-confidence. No surprise. Poor Bob Jackson is fast becoming your "star witness".
Well, he is a Pulitzer Prize winning photographer. so that makes him somewhat of a star. That also indicates that he has some good observational skills. But I have to thank you for pointing out Malcolm Kilduff whose later statements I was not aware of until you kindly pointed it out. Funny how that is: the more one digs, the more evidence one finds that the shot pattern was 1.....2...3.
Please explain how your second witness, Linda Willis, could see the President slump about the time of your first shot.
I don't have to explain. Her testimony speaks for itself:
"Miss WILLIS. Yes; I heard one. Then there was a little bit of time, and then there were two real fast bullets together. When the first one hit, well, the President turned from waving to the people, and he grabbed his throat, and he kind of slumped forward, and then I couldn’t tell where the second shot went."
All you have to do is look at the Zapruder film to see JFK doing exactly what Linda Willis said she saw...AFTER the first shot and before "two real fast bullets together". So, despite what your suspicions may be from your photo analysis, she was able to see that.
Rather than during the first two shots, Hurchel Jacks could just as well be saying Youngblood got into the back seat during the last two shots.
"He climbed to the rear of the seat with the Vice President and appeared
to be shielding the Vice President with his own body. At that time I heard
two more shots ring out."
But we know Youngblood didn't hop over the front seat even then because Johnson and him are seated in their respective seats in the Altgens photo.
I don't know what you think you are seeing in Altgens #6 but it looks to me like something is blocking a clear view of the right side of the back seat to the right of Lady Bird. What else could that be? We can see the top/side of the back of Johnson's head but we can't see Younblood's head anywhere.
Why Z282? We can see enough of Greer's face by Z277 to know he's turned around about as far as he ever got. The film also shows Greer turned around by frame 273 (when we first see his hairline clearly; it's the same as later frames).
Greer is probably turned to his right in the Altgens photo.
It is absolutely impossible to tell what direction Greer is looking in the Altgens photo. There is just shadow. But if you look at the zfilm during this time his chest and shoulders do not move at all.
Kellerman begins to turn his head to his left about the late-Z240s. Possibly, both Greer and Kellerman heard Connally shouting beginning at Z242, which finally prompted them to look back. In Greer's case, he said he heard the second shot before turning his head.
This doesn't do much for your "second shot" at Z271. You have to learn to follow the evidence.
The second shot at z271 is consistent with:
1. JBC sailing toward the front before falling back on his wife
2. change in appearance of JBC's cuff from z271-272
3. movement of the sunvisor z271-272
4. JFK's hair flying up from z273-276 as reported by Hickey.
5. Greer turning back immediately AFTER the second shot and seeing JBC falling back onto his wife. That does not begin until z278.
It is also now corroborated by secret service interviews as recounted by Gerald Blaine in his book The Kennedy Detail who reported that the second shot occurred as Clint Hill stepped off the runningboard and ran to the President's car.