A question?
If the massive star was close enough to affect our Solar Systems's early development when it went nova, shouldn't there be a relatively close (in galactic terms) black hole or neutron star. Hester suggest that the early stars drifted apart, but it still seems like there should be some sort of regional cosmic remant from that type of explosion.
A second question, could it be possible that the meteor in question drifted in from outside our solar system. I know this may be a long shot, but 4.6 billion years is a long time for something to be drifting around.
Jeff