Nice work Tim, you've cleared up so many issues including a massive error on my part regarding CE843. I thought that there were only two fragments removed from JFK's head and there appeared to be 3 fragments in the picture I posted which confused me. The two fragments from JBC's wrist can be seen in the rectangular transparent container next to the envelope in the top picture:
These are obviously the two fragments Gregory testifies to removing, which is confirmed by the pre-op and post-op X-rays.
Audrey Bell must be mistaken about the number of fragments removed and about turning them over to a plainclothes officer instead of s State Trooper (unless Nolan wasn't in uniform that day).
The envelope is surely the one that made it's from from Bell to Nolan to Fritz to Drain to Frazier.
The FBI report [30/11/63] about Gregory removing a single fragment must also be some kind of mistake.
It is also possible that Frazier labeling Q9 as a single fragment instead of multiple fragments might be some kind of convention, although in other examples he specifically refers to the amount of fragments. And in his WC testimony he only refers to a single fragment.
The only thing that hasn't really been cleared up is the picture of Q9 [FBI C9] in the National Archives:
I don't see how this can possibly relate to the two fragments taken from JBC's wrist.