They do align - with a point behind and to the car left. The shot came from behind to the car right.
They align with the camera angle. That is the point. If the camera angle is similar to the camera angle in Z193, then the space between JFK’s left arm and JBC’s right shoulder (in Z193) indicates that JBC is further inboard in Z193 than he is in the Main Street photo that you tried to use to demonstrate JBC’s position. Perhaps someone with better skills and motivation than me will compare the two camera angles and let us know if they are relatively close.
They are fairly close - less than a degree difference.
The camera sightline on the Main Street photo appears to go from the front edge of the front door handle to the left edge of the left rear handhold:
This line projected onto the limo overhead:
shows an angle from the camera to the car direction of 28.1 degrees.
The camera sightline at z193 appears to go from the front of the rear door handle to the right side of the left rear hand-hold:
This line projected onto the limo overhead:
shows an angle from the camera to the car direction of 28.3 degrees.