After careful inspection and a thorough cleaning, the intake was repaired by my cousin Jim.  We did find another small crack that had developed on the outside of the plenum – not a leak, but more of a stress crack.  At any rate, with some new weld beads, the runners are all repaired now.  This is what things look like, after the repairs:

Here is a closer look at the affected area:

The face of the flange was found to be ever so slightly not 100% flat.  With a little machining, it is now level and flat.  I started putting this all back together last night.  Should have it all running today…