The rim wasn't quite even between the top/bottom thickness around the filaments.  That bothered me, so I fixed it.

I was able to programatically create the rim based upon the filament pockets themselves, but the code was a real dog and the resulting model just made me feel dirty for creating it.  I went back to manually doing it, and so this is just a couple cylinders fit to where the pockets need to be.  It's not parametric, but it is about 100x faster and a much cleaner model.  

Perhaps I'll figure out how to determine the cylinders needed for a proper parametric model later.

Stopped the print.. printing again..