P.S. Concerning the Rebuild vs. junk. You might try contacting edlebrock---they should/might still have unsold Performer RPM (basically the q-jet replica after they took over manufacturing rights) available. i don't think they advertise this anymore. But they did recently.
i did not want to reveal that last fact, but it appears that it's unlikely that my planets will align to make getting one a reality for me. So i though i would spill the beans.
Incidentally, i wonder why edlebrock discontinued this wonderful carburetor?