Well, it's been a week, I guess no one has a fix for this issue. Or, (possibly) no one ever had to worry about this issue.
As an update, I have found that I can at least read the individual log files (XMLs) created with each render (if you've checked that option in Preferences)...
It's a bit of a kluge. I was hoping to see ALL my render logs in one place in-line within C4D. And, I might be missing quite a few of my old renders since I'm not sure I always had that option checked. Another limitation, I'm obviously only seeing one project's XML files per each folder location. And, I have to open up each individually instead of looking at them all at once for comparison. It used to be handy to cross-reference different render times and settings across projects that were saved in different locations.
But, I suppose I'll have to make do unless anyone has a way to load the info from these files back into C4D. All of this was taken care of automatically by that Render Queue log from before. Kind of a bummer I can't get that info back.
It's hard to believe this information isn't stored "somewhere" on my System. Maybe it's inside the application "package" or something?
Fingers crossed someone will come up with a solution at some point.