I finally have it running again. While I was swapping my carb out the other day, with what ultimately was a worn out carb, I noticed my Holley leaked fuel in an odd manner, and noticed the base gasket on the manifold wet on the side. I decided to disassemble, clean, and re-assemble the carb tonight. After getting it back together, it wanted to run, but I needed to adjust the timing a bit. After a couple distributor adjustments, I was up and running. I put the timing light on it and got it back to the 16 degrees I've been running.
At present, it seems it may have been a gasket issue between the main body and the base plate of the carb. This was replaced during my rebuild about a month-month and a half ago. I didn't see anything out of the ordinary with the gasket, but swapped it out for the old one I removed. I suspect this may have been the culprit, but I've not had it up and running long enough to be entirely confident in this diagnosis. The gear on the distributor still sticks in my mind, though I've not been able to get it to move outside it's normal function.
Certainly, if the carb was sucking air it could have caused all of the issues--loss of power and overheating caused by a lean mixture--still, it's sudden onset has me wondering, though. I suppose everything has a tipping point, yet I'd have thought a little more subtle indication of an issue would've shown itself prior to it's sudden and rather dramatic failure. Admittedly, the plugs showed it running a little leaner than it was prior to the carb rebuild--but it wasn't much. I chalked it up to fresh rebuild. I even bumped the jets a bit while I was in it again, just to be safe.
Well, it will have some driveway idle and close by running for a while--before I'm comfortable with a road trip again, once I re-seal these damn Cobra Le Mans valve covers--they sure are pretty, but the gaskets like to walk/deform.
I do appreciate all the thoughts and suggestions everyone offered. This website has been a great source of knowledge for the last 10 years I've had the Galaxie--with my first FE.