I've finally got my home Ubuntu server running Rails on Passgenger + Apache2. After several attempts at getting this going there were some modifications that I needed to have made in the production.rb file for it to work. Those lines that needed to be changed are:
config.serve_static_assets = true
config.assets.compile = true
Both lines are set to false for a default installation. This post serves more as a reminder for myself when deploying Rails app.