I followed the instructions on post #2683 of the homebrewtalk.com site, and now I have the watered-down index.php by default and a password-protected admin.php for making changes. And these are both visible from external browsers.
Which leads to this question: when Elco & others make updates to the web UI, and I pull these down by running “python ~/brewpi-tools/updater.py”, will the new changes overwrite these customizations? I figure inevitably I will want such changes, so I am kind of hoping the index vs. admin.php become part of the master branch.