Thanks for the suggestion. I've briefly tried Anaconda before, unfortunately can't remember why I didn't continue with it.

I just tried again and saw an error similar to what I get when I try with pip+brew - ModuleNotFoundError: No module named 'PyQt4'.

Note, this is after spending quite a while installing/removing/upgrading various qt packages and dependencies to try to resolve this. The system might be in a weird state because of that - but I originally started from scratch and only followed the instructions I found on the matplotlib site...