MediaWiki Visual Editor Parsoid 404 Error

...OK, sometimes one can miss the simple basic things and in all the searching and reading I did on this subject no one ever broached this idea.

Well, it really isn't a solution per se, but rather a suggestion in the form of a question. 

The Question

Have you checked your apache / HTTPD configuration?

I hadn't. And it turns out that was the issue. Specifically I had a simply typo in my httpd.conf file (I'm using CentOS 7.4, so the location and name of your Apache / HTTPD configuration file may vary. It may even be in multiple files.)