They refused to identify it after seven months, or, given the fact that they'd failed to put their initials on it, were unable to identify it after seven months?
PS Take some deep breaths.
In through the nose, out through the mouth . . .
I still am unable to fathom - really, I am quite dull - the central issue as to why, if CE 399 were in any sense a "plant," our dumbass conspirators would have used a bullet that raises as many obvious red flags as CE 399 and not had the various participants get their stories straight. If what was found at Parkland was actually nothing, or a 30.06 slug that you needed to make disappear because it didn't match Oswald's rifle, why would you substitute a bullet like CE 399 and coach your witnesses to tell a consistent story? And where did it come from in the first place? Was it always ready, "just in case?" How and why?
I can certainly appreciate that there would be very significant chain-of-custody issues if CE 399 were offered into evidence in a criminal trial. But in a criminal trial, you merely need to object that the chain of custody is insufficient to make reasonably certain that CE 399 is in fact the bullet found at Parkland. You don't need any rationale. But if you're asserting a conspiracy out here in the Real World, you DO need a coherent rationale as to why sane conspirators would have done what you are alleging they did.
CTers seem to miss this critical distinction. Out here in the Real World, you can't get by just by playing Oswald Defense Counsel and raising legal objections. The theory you are promoting has to make sense, or at least not blatantly Not Make Sense.