heater core leak?

That HVAC box will come out in about 15 minutes. It's not a world tragedy, I promise. I tell you what I would do. If you don't plan on putting A/C back on it, I would change it over to just a heater car. You'll need the correct heater only controls and the heater only box, but it will be much easier to work on and around in the future. JMO