I came up positive, and been feeling under the weather lately, but today I felt pretty good, and figured I'd take a safe windows-up drive around town in the Mustang.
It ran honestly the best it has since before the problems started back in August of last year. Unfortunately, the hose slipped off the pump again, and even worse, I had no zipties or tape of any kind to keep it on there. So I plugged it back on, and kept driving back home, drying and resecuring it every time it came back off.
However, I still consider this a win. For once, the car has died and I know what the problem is, I'm excited to get started fixing it.