I found a couple of issues already!  The area under the EGR is gunked up just as I suspected, and later on I will go in there and clean it up.  The plenum, as Adam's Apple mentioned, was WET with fuel.  Just a bit, but any is more than I expected.  I found a vacuum line disconnected, and I am hoping that this is the reason why fuel is going places it's not intended to go.  In the first photo, you can see a bit of the gunk under the EGR mounting.  The port to the left in the photo looked especially bad.  I am encouraged by the possibility that just cleaning this out will bring an improvement, but I found something even better.  I found a vacuum hose disconnected, and I have been suspecting a vacuum leak all along.  You can just barely make out what I suspect is the end of a vacuum line that needs to be reconnected to that chalky grey looking check valve in the second photo.  Tomorrow, I go back to class and will get the plenum cleaned up with the facilities we use for heads and blocks, and I will take a wire wheel to the EGR parts that have caked on grime.  I am going to try to keep a pile of the crud I get out of the EGR passage as best I can.  Leave a penney next to it for context, maybe!  Hopefully I won't need to replace the EGR, just clean it up.  I am going to a Corvette meet Saturday (with the C-5) so I am not sure when I'll get things put back together.  I will post that later on.

Adam's Apple!  You were correct, I hope.  I brought the plenum into school today and got it cleaned by this noisy, big machine that makes sure the clean parts are clean, but the dirty parts stay dirty.  No surprise there.  Sigh.  Anyway...  the instructor (who had GM experience back in this era) suggested that I replace the EGR valve, first of all, but also the fuel pressure regulator.  He told me that it was NOT uncommon for the diaphragm inside the regulator to tear, and that would cause the leaking I found, poor fuel economy (only got 24 mpg with those 2.59:1 gears for the trip from Charlotte to Ocean Park).  We searched a bit re: that unconnected vacuum line, and it looks like my reconnection plan is sound.  So now I will have time to go do other Corvette things while I wait for the parts to arrive, and also clean out the EGR passages.  Here's a chance for me to clean up the engine exterior and that cannot hurt either.