The assassination researcher Barb Junkarrein addressed the question of the "hole through the windshield" and specifically whether Altgens 6 shows a hole here:
https://educationforum.ipbhost.com/topic/14532-barb-junkkarinens-articlea-hole-through-the-windshield/
Key graf: "Good copies of the Altgens photo show it [i.e., the alleged hole or "spiral nebula" crack] to be not a feature of the windshield. Rather it is a pattern formed by the gathering of fabric in the dress of a woman spectator standing in the background. The Altgens #6 photo demonstrates that the limousine windshield is not damaged at Zapruder frame 255.
Already posted (and predictably ignored by MTG).
