Great, thank you!
I added the tubing and reinstalled the carbs...and nothing happens when I try to start it. I've never really been down this rebuilding rabbit hole before, so naturally I've run into another issue.
At the risk of asking a loaded question, "what now?" I've pulled the carbs and sprayed starting fluid directly into the head and all four cylinders fired, first kick. I put the carbs back on and nothing happens when I try to start either way, kick or electric start. You can hear it turn, but there's no catch. At all, not even a cough. What would be the next step in troubleshooting?
I appreciate the help and patience while I learn to tackle this!