I would agree, Rob, that the WC's conclusions are "sunk", but not because of the confusion regarding the head wounds.
Many of the witnesses you cited were shown the autopsy photos and deferred to their accuracy. Some were asked to point out the head wound location they'd described as being on the back of the head, and pointed to a location above the ear, its location in the autopsy photos. In any event, there is no consensus for a wound LOW on the back of the head--where most CTs place the wound after being shown the so-called McClelland drawing, and being told this is where the Parkland witnesses placed the wound.
The confusion spread through a series of steps.
1. Some witnesses thought shots came from in front of Kennedy.
2. Some witnesses thought they saw smoke on the knoll.
3. Several Parkland witnesses thought the large head wound was on the back of the head.
4. Several Parkland doctors saw scrambled brain fall from the skull onto the stretcher or floor and assumed this was cerebellum.
Well, this ia pretty convincing. But when you look closer it begins to fall apart.
1. A number of witnesses thought the large head wound was on the top of the head, not back.
2. A number of those who said it was on the back of the head pointed out a location on the top of the head.
3. Most of the "cerebellum" witnesses came to claim they could have been mistaken, or that they saw cerebellum while looking down into the skull from a wound at the top of the head, and that, in any event, there was no blow-out wound on the back of the head between the ears, where most CTs place the wound.
Well, this leaves open the possibility the wound was actually at the top of the back of the head, a couple of inches behind where it is shown in the photographs. But it makes little sense to me that the autopsy doctors would be a party to concealing a wound in this location...since this is where they placed the wound in the drawings they'd had created from the commission.
No, I think it's far better to focus on the wound location they moved for the drawings--the back wound. The movement of this wound by the WC is, for me, the proof of the cover-up. And I'll go further than that. IF the HSCA had focused on this one aspect--who moved the wound for the WC's drawings, and why--they would have buried the WC's reputation. But no, they let Specter off the hook, which perhaps wasn't all that surprising considering he'd finagled his son onto the HSCA's staff.