Getting the wiring worked out. Had to turn the solenoid upside down as I had the battery on the I post and the alternator on the S post. Marked them with paint so that shouldn’t happen again. Good news is the kill switch works and the starter spins right up. Kind of cool and terrifying at the same time to hear the truck attempt a come to life moment.
Now that the solenoid’s wired correctly, chasing down why the power wire to the fuse box doesn’t have power. Thought it might be a bad join in the wire when it was extended but dad remembers a wire being “soft” in one spot… of course that’s the power wire.