Flux Capacitor Solenoids
Two tiny black posts protrude from the surface of the vacuum solenoid. Connected to each is a single black wire. These are posts for soldering the wires that will power the solenoid. The black wires are connected to the coil inside the round metal case. The posts look simple enough but finding something now that matches these would be a trick.
Fortunately they resemble some other electrical components. I have a hand full of test probe sockets (also called Tip Jacks) that look an awful like what we need. And they are exactly the right size.
Here's the soldering posts placed on my solenoid replica. I added the wires that are wrapped around the top of the posts and go into a hole in the base.