That looks like the perfect wrench Jim! I may need to get one. Anyway, the '51 HJ and '52 HJ Vagabond originally used Autolite starters which have a small, relay, often mis-identified as a 'solenoid' on them. They have a single, 16 gauge wire which runs up to the starter button. Pushing the starter button grounds the coil in the relay via that wire, putting the contacts together to supply 6 volts to the starter from the battery. When the starter spins, the drive gear is engaged to the ring gear on the flywheel using centrifugal force. The '52- '54 models have a Delco-Remy starter which had a large solenoid on it which does two things - engages the starter drive gear with ring gear on the flywheel by shoving it backwards, then closes a relay inside it to apply 6 volts from the battery to the starter to turn it. The Delco unit has 12 gauge wires going to it! It takes a lot of current to do it's job and in my opinion, the starter buttons is too light to operate it for very long. NAPA used to carry an exact replacement but not any more. I've found some at Fleetfarm and grabbed 'em all up.