After many hundreds of thousands of search/replace and other tweaks on the code base, along with local testing using a tweaked hosts file and Apache with a self-signed cert, I've now pushed all 26GB of stuff up to hcmc/www/eol, where it will live, and asked sysadmin to organize new virtual hosts files on HCMC's clusters followed by switching the DNS. Not everything works, but most things do, and many will be easier to fix in-place live than in a test setup.