Circled in red.

When I pulled one of the vacuum lines off fuel came out of it, making me think it's some sort of fuel pressure regulator --- with a torn diaphragm, perhaps?

The vacuum line I'm still looking for a connection to has a red line on it. It's connected to manifold vacuum on the top, its the 4th of the 4 metal vacuum lines in the "pipe gallery," the one closest to the firewall. I can't figure out where the end at the bottom is supposed to connect.

ZX? Looks like a BCDD. No reason for fuel to come out of the hose though.

Are you sure it isn't water? Strange as that sounds, I found water in some vacuum lines after a rainstorm in my '81 a few years back. It gave me all kinds of trouble until I figured it out and pulled some of the lines to let them dry for a few days.

If it's fuel, I would think you'd have more problems with your vacuum system, since it would probably mean that something is misconnected in a pretty drastic way.