So I've been poring over the vacuum diagrams I've found, and can't make sense of what's going on my car. The previous owner appears to have cut one vacuum line and stopped up another with a nail! Many of the tubes and joints are newish, so no helpful color coding. Anybody know what these are supposed to be doing?

1. This is what's coming out of the firewall on the driver's side. (What's the technical term for this bundle of tubes?) The prominent thin black tube coming from the upper right is cut and just loose in the engine:


2. This is the central plug (at least, I think that's what it's called). Note the nail in the rightmost tube.



Pardon my naivete -- this is the first car I've delved into.