When you renamed the copied script, did you change the actual class name in the script? Try creating a new script with:

class Testscript < OpenStudio::Ruleset::ModelUserScript
   def name
    return "Test"
  end
end

Testscript.new.registerWithApplication

After a restart you should see it. I suspect you didn't before because the application had already loaded a script with the name in your copied files.